


The Thickened Light

by mundungus42



Category: Harry Potter - J. K. Rowling, Les 120 journées de Sodome | The 120 Days of Sodom - Marquis de Sade
Genre: F/M, Marquis de Sade - Freeform, Masturbation, Mystery, Romance, Suspense, discussion of rape and torture, magical theory, rude dreams, schoolgirl fantasies, seriously adult subject matter, vampire cameo
Language: English
Status: Completed
Published: 2011-11-23
Updated: 2011-11-23
Packaged: 2018-10-23 15:03:54
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 3
Words: 21,608
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10721733
Author URL: https://archiveofourown.org/users/mundungus42/pseuds/mundungus42
Summary: Hermione finds signs of a health threat to the wizarding world near a hidden chateau in Avignon, but is she prepared for what she'll find inside?





	1. Chapter 1

**Author's Note:**

  * For [condwiramurs (Aurys)](https://archiveofourown.org/users/Aurys/gifts).



> Written for condwiramurs for the Autumn 2011 round of the the SSHG Exchange to the following prompts: 1. Aversion to silver and aconite prevents Snape from brewing Wolfsbane, so Hermione must do it. 2. Hermione discovers something that convinces her that Severus is a loyal Death Eater. 3. On holiday abroad after the war is over, Hermione discovers Snape and a new and unexpected threat to the wizarding world (bonus points for bringing in Lucius). Please note that this is a finished work that was written for a specific recipient to particular prompts, and as such, concrit is not being solicited.

Hermione stands at the precipice where the ancient bridge ceases to be, as if searching the water below for answers. Ominous clouds overhead promise rain, and the riverbanks are deserted, despite it being just after seven in the morning. The cool, damp air makes her fingers ache, and she gathers her left hand to her chest, gently massaging the skin against bones that, once crushed, not even magic could fix completely. The old injury troubles her little — she only notices it when her mind isn't otherwise occupied.

And yet, facing the edge of the broken bridge, she can think of nothing to distract her. She is afraid of the unknown but knows there is nothing here but what lies ahead. Squaring her shoulders, she steps forward into empty air.  


~o0o~

Eighteen years and sixty-seven days prior, Hermione, now in her sixth year at Hogwarts, prepares to take a similar step into the dimly-lit Potions classroom, entering it not as a student, but as something different.

The tools she needs are laid out on the workbench, and the cauldrons that Professor Slughorn piles artistically on his desk have been hastily shoved into the corner. Professor Snape stands at his former desk and flicks his wand at the door, fastening it behind her. She stands, waiting for instructions, but he crosses his arms and looks down his nose at her.

'Well?' he asks querulously.

'I'm here to brew Wolfsbane Potion, sir.'

'Obviously. I would be in my quarters, else. Is there any particular reason you're standing there as if Confunded?'

'The ingredients—'

'Are in the supply cupboard. Surely I needn't list them on the board.'

Not trusting herself to say anything that won't annoy him further, she ducks into the cupboard and gathers what she needs: aconite harvested during the full moon, silver, brimstone, ginger, and Acromantula venom, a few botanicals as stabilisers — it doesn't matter which ones. When she returns to the room, she is surprised to see that Professor Snape's upper body is encased in a Bubble-Head Charm.

It is only the Half-Blood Prince's copy of _Advanced Potion-Making_ in her bag that stops her from asking him about it — the last thing she wants to do is draw attention to herself. He is bent over his book ignoring her — a sure sign that he expects her to fail. However, this potion is not for class. It's for the Order, and she knows that means Professor Lupin. It's for his sake that she has swallowed her pride and stolen the book from Harry's trunk. He won't miss it — he's meeting with Dumbledore tonight, or so says the note she wasn't supposed to read.

She glances at Professor Snape one last time to ensure that he's still engrossed by his book and lays the precious textbook on the workbench. The Prince's comments for the first stage of brewing are copious, recommending four anticlockwise stirs where none are mentioned in the text and adding the ginger while the potion is still thin, among other heresies. But she can't argue with Harry's results, and she is willing to trust the Prince, just this once, for the greater good.

Three hours later, Hermione is breathing hard, assiduously trying not to let sweat drip into her cauldron. The ingredients for this stage may be few, but they are added in different combinations at different times in different preparations, and Hermione's hands ache from all the grinding and chopping. However, there is only an infusion of crushed ginger in Acromantula venom left to add, and then the potion must simmer for a day.

Since she has committed the final instructions to memory, Hermione casually returns the book to her bag and sets to crushing the ginger root with her mortar and pestle. The task is relatively mindless, and Hermione glances at the front of the classroom, where Professor Snape sits, absorbed in his book. Something about the light displeases him, and he lifts the book and sets the top on another book so as to render it a more comfortable angle for reading.

She feels a flare of irritation. Professor Dumbledore gave him explicit instructions to supervise her brewing, and he's been buried in his book all evening and hasn't looked up once. She glances at the ginger and notes that it's stringier than it should be. Perhaps the ginger root is too old? Unfortunately, the Prince has no suggestions for dealing with ginger— perhaps he assumes it's obvious.

Hermione squares her shoulders. Professor Snape is going to advise her, whether he likes it or not. 

She continues crushing the ginger as she approaches his desk.

'Sir? I think there may be something wrong with the ginger.'

He looks up with a frown and sets his book aside. The gold leaf stamped on the peacock blue cover catches the firelight.

 _The 120 Days of Sodom_ by Marquis de Sade.

In her surprise, her hands lose their customary dexterity, and she cries out in pain as her pestle crushes two unlucky fingers.

Professor Snape is at her side in an instant.

'Clumsy fool.' He seizes the mortar and pestle and crushes the ginger to the correct consistency by adding a clockwise grind as he pounds. He flies to her workbench in a flutter of black robes, adds four drops of Acromantula venom, and scrapes the mixture into the cauldron, which obligingly lets out a puff of purple steam. It's finished, for now.

Despite the agonizing pain in her fingers, Hermione is in awe of his swift, sure movements.

'You are excused from cleaning up the mess you made. To Madam Pomfrey, before you damage yourself further.'

He grabs a handful of sparkling powder from an ornamental pot on the desk, which he tosses on the fire. The fire blazes green, and she gives him a pitifully grateful look as she steps into the flames.

'Hospital Wing!' she says, and she feels herself snuffed out of the Potions classroom only to burst into being three floors above.

Madam Pomfrey looks up from decanting Pepper-Up when Hermione appears in her fire. 'Gracious, child, whatever is the matter?'

She holds out her hand, and the matron springs into action, ushering her to a bed and producing a phial of creamy blue potion that makes her drowsy. As Madam Pomfrey points her wand at Hermione's mutilated digits, she knows there is something she must remember, but everything is muddled. She closes her eyes.  


~o0o~

In the present day, Hermione steps into nothingness, and it bears her up.

She lets out a shaky breath. She hadn't really fancied a morning dip in the Rhône.

Where the medieval bridge ostensibly stopped is an impressive array of charms intended to discourage magical and Muggle visitors. Beyond it, the bridge stretches to the _Île de la Barthelasse_ , but standing between her and the island is a handsome, comically narrow house. She strongly suspects that, like Grimmauld Place, the house is much larger on the inside.

An eerie cry pierces the silence, and Hermione spies a white peacock eyeing her suspiciously from atop an ancient hitching post. Up close, the bird is quite ugly, with scaly skin visible in places, and its tail feathers are grey with dust. But the bird is beautifully shaped, and it holds itself with great dignity.

As she approaches the front door, she tries not to think what the presence of the bird portends. She raises her hand and knocks.  


~o0o~

On the second night of brewing the Wolfsbane, Hermione's tentative knock reveals her scowling teacher, his head already enclosed in an orb of fresh air. He seizes her left hand to inspect Madam Pomfrey's work. Her fingers, though healed, are black and blue, and he frowns.

'Can you brew?'

'It aches a bit, but I can work through it.'

'Overconfidence will not serve you today,' he says, releasing her hand and stalking over to the desk. 'The brewing you do today will make yesterday's seem like a cure for boils. You must be painstaking, precise, and above all, aware of where your body is at all times. The slightest mistake could prove fatal to the drinker. If at any point you find yourself unable to complete a step in time, you will Vanish the contents of your cauldron and begin again when you are fully healed. Have I made myself clear?'

'But the next full moon is in a week! Professor Lupin—'

'Lupin survived his childhood and adolescence without the luxury of Wolfsbane. I daresay he can go without for a month, especially when he has no-one to blame for the lack but himself.'

'I don't understand.'

'It is not necessary that you understand,' he says sharply. 'It is, however, necessary that you begin brewing immediately. You recall where the Boomslang skin is, I trust?'

The reference to her illicit second year Polyjuice causes her cheeks to redden, but she suppresses the urge to flee and opens the cupboard with what she hopes is convincing nonchalance. Her fingers throb as they close around the bottles and jars she needs, but she grits her teeth, sets the bottles on her work bench, and commences chopping.

She glances at him before pulling the Half-Blood Prince's text from her bag and upsets a bottle of powdered ergot when she recognises the blue and gold cover of his book. She shakes herself mentally. No matter how vile, disgusting, and horrific Professor Snape's reading matter, these are exactly the sorts of distractions she cannot afford tonight. 

She sets aside the book, takes a deep breath, and allows herself a moment to contemplate what sort of person would read such a book, in a school of all places. Not that she's read it, of course. But what decent person has?

Scowling, she brushes up the spilled ergot and resumes laying out her ingredients. Better to ignore the man completely than to let herself contemplate the implications of his leisure reading. 

Hours later, she is breathlessly triumphant. The Prince has guided her through another evening, and the Wolfsbane is a perfect shade of chartreuse and emits bubbles every three seconds, just as it ought. She nearly jumps out of her skin when she realises Professor Snape is standing behind her, staring at the contents of her cauldron. She steps aside in what she hopes is an appropriately deferential manner to stand between him and the precious textbook.

He gazes at the potion but can find no fault in its appearance. 'What does it smell like?'

The Prince says that it should smell like cooking beets, and it does, but she instinctively knows not to appear too knowledgeable, lest she arouse his suspicions. She wafts the wisps rising from the surface of the cauldron gently toward her face. 

'It smells sweet, like roasted vegetables,' she says, kicking herself for not coming up with a better description.

After interminably long seconds, he nods, and she nearly faints with relief.

'Lupin may yet live to be killed another day. Now, clean up this mess and return to your dormitory.'

In her relief, Hermione's hands are clumsy as she cleans her tools, and she is positive that she feels his eyes on the back of her neck as she works. The knife she washes slips from her aching fingers and clatters noisily in the sink. She glances behind her just in time to see his head snap up from his book and glare at her. 

When the bench is so clean that not even Professor Snape can find fault with it, she bolts from the room, determined to leave the Prince's book safely in Harry's trunk for the final day of brewing. She will need her wits about her tomorrow, and the fewer things she has to worry about, the better.  


~o0o~

Hermione hears her knock echo down what she imagines are endless corridors of stone, but a house-elf opens the door immediately, revealing a warmly lit entryway with a grand staircase curving upward toward a massive iron chandelier. The elf scrutinises the St. Mungo's badge she holds out to him, by way of explaining her presence. They both know it has no real meaning, but he courteously stands aside and gestures for her to enter.

'If Miss will wait here, Batty will be informing the Master.'

'Thank you, Batty.'

'Would Miss like tea?'

'Yes, thanks.'

Batty disappears with a pop rather than a crack, which is, she supposes, the mark of a posh house-elf. The entry hall is largely empty, but for a large embroidered tapestry hanging on the wall. It bears an uncanny resemblance to the famous one from Bayeux except that its combatants move and brandish wands, and the Latin inscription reads, 'Here is Guillaume Malfoy making it rain fire.'

Her fingers tighten around her wand, and she momentarily considers fleeing, but another elf appears with a steaming cup of tea that smells like heaven. Rumour had it that all the Malfoys have resided in France since the end of the war, but suspecting something is entirely different from encountering it in reality. The tea is, thankfully, as English as it is strong.

Hermione is surprised that she feels as calm as she does standing in the foyer of her mortal enemy's home, and is even more surprised when Batty reappears, announcing that Master Lucius has invited her to breakfast. She takes a fortifying mouthful of tea and follows Batty down the corridor.  


~o0o~

On the third and final night of brewing the Wolfsbane, Hermione finds the door to the Potions classroom wide open. Professor Snape glowers at her from inside his protective bubble, but instead of ignoring her, he watches her every move as she lights the fire, sets her cauldron atop it, and disappears into the store cupboard.

His close attention can only mean that he knows something is amiss. Hermione stifles a wry snort. Only Professor Snape would consider a student's success at brewing a fiendishly difficult potion to be a sign that something is wrong. Fortunately, she has brought only her brewing notebook. The Prince's instructions are of course integrated, which was quite easy because each annotation corresponds to an instance of the potion deviating from what's described in the book. She's learned a great deal from the Prince already: that a potion that appears too dark in colour can be corrected by anticlockwise stirring, and that feverfew can safely be used to thicken any potion containing snake bile.

She returns to her work bench with the final ingredients: aconite root, ingredients for an anti-emetic potion, grains of paradise, and Quintaped liver—an ingredient she's never worked with before. She's soon grateful to the Prince for suggesting dragon-hide gloves while preparing it, since the liquid that seeps out eats fissures in the wooden workbench and reeks of alcohol. She glances at her teacher, who is still glaring down at her like a giant vulture and wishes he could, for once, be as helpful as the Prince.

After preparing the ingredients and laying them out in sequential order, Hermione tosses chopped hawthorn blossoms into the cauldron and begins to stir the runny potion. She methodically adds ingredients, stirs until the delicate pink petals have turned purple, and lays her stirring rod aside. She has fifteen minutes before the next ingredient can be added. She makes a note that next time she can save time at the beginning by using the intervals for preparing the next set of ingredients. When she finishes recording this observation, she looks up and sees that Snape is reading the book again, having clearly given up on catching her in the act of doing anything suspicious.

Hermione has not been idle between brewing sessions and has corroborated that de Sade was every bit as vile and disgusting as she had supposed. In fact, he's even worse. He hadn't simply been a powerful man who took pleasure in exploiting and humiliating people, he had also been a wizard who did unspeakable things to Muggles with magic. _Les 120 journées de Sodome_ is his encyclopaedia of perversions, humiliations, and tortures. An edition of the book that contains only the nonmagical sections is widely available in the Muggle world, but the full version that describes all four months of horror written in loving detail isn't available in the Hogwarts Library, not even in the restricted section. 

It's true, the atrocities in the book are being committed against fictional characters by other fictional characters, but after being freed from the Bastille after the Revolution, de Sade made it his life's quest to achieve ultimate sexual freedom, going so far as to enslave and murder to satisfy his desires. The floating bodies of the Muggles at the Quidditch World Cup drift into her mind's eye, and she shudders.

Professor Snape continues to read, unaware of or ignoring her scrutiny. She can't draw her eyes away from his face. The corners of his mouth are drawn downwards, his lips compressed, and she catches a dart of his tongue as he licks his finger to turn the page. There is an intensity is his eyes as they travel back and forth over the lines of text that frightens her. He shifts perceptibly in his chair, and a horrifying thought occurs to her. Is he aroused by what he's reading? 

The thought hits her stomach like a Bludger. She has always considered Dumbledore's unshakeable faith in Professor Snape to be sufficient reason to trust him. But now, far from Dumbledore's gaze, she is acutely aware that she is alone in a room with a confirmed Death Eater who, by all appearances, is finding pleasure in fictional accounts of women and children being forced into sexual slavery and tortured. She is not afraid for herself at present, since she has an important task to do. But it does raise the question of what this man, who is clever enough to satisfy two masters, truly wants. Dumbledore can grant his freedom if their side ultimately triumphs, but Voldemort, who views Muggles and Muggle-borns as sub-human, could give him the power to do as de Sade had once done. What does he desire more: freedom or power?

Her musings abruptly cease as Professor Snape raises his head and glares at her. Her cheeks redden, and she is immediately ashamed of her sordid musings.

'How long has the potion been sitting?' His voice sounds slightly tinny through the membrane of the Bubble-Head Charm.

Hermione consults her timer and wills her voice to remain steady. 'Seven minutes.'

'Make sure the steam rising from the surface is no darker than cobalt before adding the grains of paradise.'

This instruction runs counter to both the book, which suggests cornflower blue, and the Prince's advice to wait until the steam is navy. However, Professor Snape will know if she disregards his advice, so she nods. Better the devil you know, as the old saying goes. He gives her another scowl and returns to reading. 

The timer is agonisingly slow, but it finally chimes. Hermione picks up the dish containing the grains and when the pale steam rising from the potion's surface darkens to cobalt, she sprinkles the shrivelled seeds evenly over the surface. She raises her wand and draws spirals in the steam, and the bubbling liquid darkens to silver, its surface taking on an iridescent sheen. It's another seven minutes before the liver goes in, and she sets the timer for six minutes so she has the opportunity to pound the diced liver with a mallet immediately before adding it.

She allows her gaze to wander back to the man reading at the desk he had occupied until this year, and she marvels that she's been obsessing over his reading matter rather than contemplating the circumstances under which she currently labours. Belatedly, she wonders if that isn't the reason he chose to read that particular book—to distract her from the numerous curiosities about the situation.

Curiosity 1: Professor Snape is no longer teaching Potions. Harry insists it's because Snape's always wanted the Dark Arts post, but she isn't convinced. Frankly, he seems no happier teaching Defence than he did teaching Potions.

Curiosity 2: Professor Dumbledore said that Professor Snape is no longer 'able' to brew the potion, though she can see no physical limitations.

Curiosity 3: He casts a Bubble-Head Charm when the potion emits any kind of fumes. 

Conclusion: Breathing in whatever vapours the potion releases is detrimental to Professor Snape's health. Given that many of the same ingredients are used in sixth-year Potions, Professor Snape's sudden promotion to Defence makes a bit more sense.

Curiosity 4: He looks unwell. He always looks ill-rested, but his skin is paler than usual, and the dark circles under his eyes are more pronounced than they were even a week ago.

Curiosity 5: Professor Snape said that Professor Lupin was at fault for the situation. 

The pieces begin to fall into place.

Curiosity 6: Professor Snape has not covered werewolves in depth in Defence Against the Dark Arts, despite Fenrir Greyback's numerous attacks at Voldemort's behest.

Conclusion: At some point in the past year, Professor Snape has been bitten by a werewolf, possibly Professor Lupin. Therefore, he is more invested in seeing the potion completed correctly than he lets on.

Hermione is giddy with discovery and lets out a huff of satisfaction. Professor Snape looks up from his reading sharply, and she turns toward the potion, not trusting herself not to give herself away. She can even admire his cunning distraction—of course the Insufferable Know-It-All would become obsessed with a book and miss the obvious.

The evening passes in cycles of bubbles and steam. When she is finished, he examines her cauldron's contents with an unreadable look on his face. When he speaks, his voice is soft.

'Unless I misread Professor Slughorn's syllabus, you have not studied Wolfsbane, nor have you ever had the opportunity to brew it before. One wonders who taught you to brew it.'

Hermione manages to keep her features neutral as the perfect response springs from her lips. 'You did, sir.'

She will not grasp the ironic truth of her statement for many months.

~o0o~

Malfoy's dining room has a bank of windows looking out on the Rhône and is empty but for two house-elves laying out breakfast on the sideboard and her host, who is seated at the head of the table in a pewter silk morning robe.

Perhaps the years of quiet life have improved him, or perhaps she's simply able to appreciate it now that she's not in mortal peril, but she is momentarily taken aback by the striking figure he cuts, simply sitting there regarding her with curiosity rather than hostility. The colourless light from outside flatters his impossibly pale hair.

'Hermione Granger.' 

'Lucius Malfoy.' It's a challenge to keep calm as her heart begins to pound. 'Thank you for your kind invitation to breakfast.'

'Not at all,' he says, crossing his legs. 'Anything I can do to assist you. This is an official investigation, is it not?'

'Nothing so formal. Just a friendly visit.'

As soon as the words are spoken, she knows she's made a mistake. Lucius's indifferent expression does not waver, but it's as though the air around him freezes.

'To what do I owe the honour?' he asks, fingering the lapel of his robe in such a way as to suggest the wand hidden beneath. 

'Magical allergies,' she says, hoping forthrightness will win her points. She is rewarded with seeing Lucius momentarily at a loss for words.

Not wishing to stay any longer than necessary, she doesn't let Lucius flounder for long. 'I observed something curious on the _Pont Saint-Bénezet_ and I followed it to your door — nothing untoward, of course. If you can spare a few moments now, I'll be happy to explain.'

His wand hand relaxes and he brushes away a piece of non-existent lint before returning his hand to his lap. 'Moments I can spare. Even minutes, if you desire breakfast.' He gestures at the buffet.

The breakfast betrays Malfoy's long residence in France. In addition to eggs, bacon, toast, and tea, there is _pain au chocolate_ and a pot of strong coffee. Though she doubts her stomach is settled enough to eat much, she fills her plate and sits in the chair indicated by her host. He allows her a few bites of toast before beginning the interrogation.

'At your leisure, Hermione.'

She ignores the little hiccup from her insides at the way he says her name. 'In the past twenty years, we've noticed a marked increase in patients seeking treatment for severe sensitivity to things like potion ingredients and magical creatures. And I don't mean simply sneezing or watery eyes. We believe that the wizard or witch's internal power attacks a magical source outside the body, like potions or charmed objects, and with enough exposure to the allergen, we've seen cases of severe magical depletion, and even death.'

'Interesting,' says Lucius, clearly meaning the opposite.

'One patient had to give up his wand because his own magic attacked the dragon heartstring core.' 

'My own granddaughter developed a sensitivity to the winged pony her father bought for her fifth birthday. Terribly sad.'

'Quite,' says Hermione flatly, trying not to sound annoyed by his frivolity. She almost prefers the quieter, more dangerous version she knew before. 'We haven't yet determined why a witch or wizard's magic would become so damagingly fixated on another magical source, but we've found a way to diagnose it.'

Lucius merely raises an eyebrow. 

'When the body's magic directly attacks an external source, the magic is broken down into components. We've developed a test to detect the residue and track where allergic reactions are occurring.' She says this very fast.

'You are to be congratulated, I'm sure,' he says, not bothering to disguise the irony in his voice. 'And this has brought you to my doorstep?'

'I'm in Avignon on holiday. When I visited the _Pont Saint-Bénezet_ , I noticed unusual levels of the residue, and the closer I got to your home, the stronger the readings.'

'Do you frequently bring your work on holiday?'

She holds out her arm. 'The meter is in the face of my wristwatch,' she says. 'It's normally blue but gets redder when the particles are around.'

Lucius examines the face of her watch, which is bright purple. 'I see. And what do you suppose it means?'

'I haven't a clue. But don't you think it's worth looking into?'

He gives an elegant shrug. 'Perhaps. But you, dear girl, are on holiday, and I have guests who will be arriving for breakfast very soon.'

She hesitates. This isn't going to be easy. 'I don't know that this can wait,' she says quietly. 'As far as we've been able to determine, the residue only exists in the presence of someone suffering from a severe magical allergy. Whatever the source is, it's far better if we identify it straight away, since there's no guarantee that it'll be here when I get back.'

'And if I regretfully decline to have my home searched?'

'Then I leave,' she says. 'However, these readings indicate unheard-of levels of allergic response. If one or more of your guests is in distress, I might be able to help him or her.'

He looks at her appraisingly. She knows she's been bold, but he must understand the facts before making a decision.

'I suppose I'd be a bad host if I allowed a guest to expire without explicit permission to do so. You may stay until you've satisfied yourself that none of my guests is dying.'

His words make her inexplicably nervous. 'Thank you, Mr Malfoy.'

He gives her a cool smile and rises to refresh his cup of coffee. She deliberately relaxes the hand that's been gripping the handle of her wand since she saw the tapestry.  


~o0o~

When Hermione returns to the Potions classroom to brew the Wolfsbane the following month, she finds Professor Snape even more peevish than usual. This is not surprising, given that the moon is waxing and will be full in a few days, and his temper was a sight to behold at the same time in the last lunar cycle. Because that full moon fell on a Saturday, she had no opportunity to observe him the morning after. This month, the moon will be full on Monday, so she will be able to observe the after-effects of his transformation and to what degree her potion helps. She is determined to make this month's batch even better than last month's.

Wordlessly, she gathers the ingredients from the cupboard and starts chopping, slicing, and crushing. She recalls Professor Lupin's complaint about the potion's disgusting flavour, so this month she's decided to use fresh mint as a stabiliser. She doubts it will affect the final taste much, but at least she feels as though she's doing something to address the problem.

When she adds the aconite, Professor Snape casts the Bubble-Head Charm, which satisfies her not only because it means he's paying attention to her, but also because it supports her werewolf theory, since aconite is the potion's namesake. Her motions are surer tonight, and the first stage takes her twenty minutes fewer than last time, and her fingers survive the ordeal intact. When she finishes, she sees that he is still bent over the offending volume, but she musters her courage and approaches his desk.

'I'm finished for tonight, sir,' she says. 

He waits a few seconds before insouciantly looking up. He doesn't meet her eyes. He simply gazes at the potion. He gives an inarticulate grunt and waves his hand dismissively towards the door.

Hermione truly doesn't expect any words of encouragement or, Merlin forbid, congratulation, but this brusque brush-off sets her teeth on edge. 

'I used fresh peppermint this month. I thought it might improve the taste.'

He looks up from his book and scowls at her. 'It won't. Now remove yourself from my presence so I can get some actual work done tonight.'

Only the least bit abashed, she returns to her workstation, scribbles a few notes in her Wolfsbane journal, and puts her belongings into her bag.

'Still,' she says, hoping the brightness in her voice sounds less affected to his ears than to hers, 'at least you have the chance to read.'

His face flushes, giving him a feral aspect. 'Five points from Gryffindor for utter inanity.'

She is simultaneously elated at having got his full attention and thrilled by his anger. Clearly she was mistaken—he is not reading the book just to distract her. He seems genuinely disconcerted, and his anger is suddenly intoxicating. She can't help meeting his eyes. 'Is it a good book, sir?'

As quickly as his ire flares, it ebbs, and his face is the empty mask she is accustomed to seeing. 'Twenty points, Miss Granger. Care to make it fifty?'

She flees, immediately regretful that she has lost twenty-five house points for Gryffindor. It's not only because Harry is earning more points in Potions than she is, which rankles, but also because N.E.W.T.S. classes are full of the very best students, and it is more difficult to distinguish herself. Still, she can't help but feel she's gained something more valuable than house points.  


~o0o~

Hermione can't decide whether it would be a good or a bad thing to see any other former Death Eaters at Malfoy's. On the one hand, it would be terrifying and traumatic. On the other hand, she'd know what she was dealing with. However, it turns out to be a pointless line of thought, since Hermione doesn't know any of the dozen or so people who trickle in to breakfast. 

Several of them look at her curiously, the unknown witch sitting at their host's right hand, but say nothing to her as they fill their plates and eat. Hermione can't understand why she feels increasingly unsettled, but she continues to monitor her wristwatch, which remains stubbornly grape, never growing redder or bluer. To her relief, none of Malfoy's guests appear ill in the least. 

For his part, Lucius says little until the guests finish eating, at which point he begins to discuss the day's activities. Hermione takes this as her cue to leave and gives her host a quick nod, puts her serviette on the table, and rises.

'I trust you're satisfied, Hermione?' 

There is a strangled sound from the end of the table, and Hermione sees that an older gentleman with snow-white whiskers is turning red in the face. She rushes to his side.

'Are you all right, sir?' she asks. When he fails to answer, she wraps her arms around him and pulls in sharply just below his sternum. A piece of croissant pops out of his mouth on to the table. A few of the guests make disgusted sounds, but Hermione only cares about the man with the whiskers, who takes an enormous, shuddering breath and begins to cough.

She Vanishes the croissant and casts Aguamenti into his empty teacup. He drinks, nodding gratefully, and continues to cough into his handkerchief. He rises, squeezing Hermione's hand gratefully, and gives Lucius an apologetic bow as he excuses himself from the table. 

Hermione envies him the grace of his exit, even as the guests murmur. She gives Lucius a curt nod, which he returns, and she makes a beeline for the corridor that leads to the entrance hall.

She manages to find her way to the door after only a few wrong turns and is a few steps from the broken edge of the bridge when Batty the house elf appears.

'Master Lucius asks if Miss will stay.'

Hermione trips on the edge of a stone, and it's only her proximity to the hitching post that keeps her from falling on her face. 'I don't understand.'

'Master Lucius is grateful to Miss for saving his friend and would like to make up for past misunderstandings.'

'I really don't think—' says Hermione.

'Master Lucius is most eager for Miss to stay the night,' says Batty, twisting his ear with a plaintive look on his face. 

It's the ear-twisting that does it. Hermione sighs. 'I'm staying at the _Gateau du Fromage_ ,' she says.

'Batty will ensure that Miss's things are seen to,' says the elf, bowing gratefully. 'Now, if Miss would like to finish breakfast in the kitchen, Master Lucius would like to see Miss in the library afterwards.'

Hermione tries to ignore the excitement that sparks to life at the mention of the word 'library.'  



	2. Chapter Two

The second night of brewing passes uneventfully, but Hermione's dreams are full of Professor Snape looming over her, looking down at her as if she were a piece of filth stuck to his shoe. He sneers at her, but his words are drowned out by the pounding of blood in her ears. He raises his wand and aims it between her eyes. She can feel his consciousness slide into her unresisting mind, and she feebly struggles as he peruses her darkest suspicions about him and her obsession with his book. He withdraws completely from her mind.

'Is this what you fear?'

She is utterly at his mercy, and her whole body quivers with anticipation. 'Yes.' Her voice cracks on the syllable.

He leans over her, and his face is so close to hers that she can feel his breath on her face. 'Is this what you want?' 

'Yes,' she whispers.

His wand slashes through the air, and her body is hit with a powerful spasm of pleasure that jerks her into wakefulness, her nightdress twisted between her legs.

She does not sleep the rest of the night, and her thoughts are a tangled mess when she steps into the Potions classroom for the final stage of brewing. She is fifteen minutes early, and Professor Snape has not yet arrived. She casts a furtive look over her shoulder before approaching his desk and opening the drawers in search of the book. Unsurprisingly, it is not there. 

She doesn't wholly understand why she can't stop thinking about the book. She tells herself it's because the book is rare and valuable—the only bookseller who has a copy is in Knockturn Alley, and they've priced it at five hundred Galleons. She tells herself that it's an exercise in thwarting censorship, since it's the only book she knows of that can't be sold to underage witches and wizards. She even manages to convince herself that once she reads it, she'll know if Snape is truly Dumbledore's man or Voldemort's. Even now, without complete understanding, there's a part of her compulsion that she doesn't want to examine.

She shakes her head as if to clear it and realizes that her hair has escaped its elastic. Tonight is the final night of brewing, and it won't do to have the previous days' painstaking work ruined by carelessness. She twists her hair into a tight bun and casts a Freezing Charm on it to keep it in place.

A glance at the clock tells her she's still ten minutes early, so she lights the burner and puts the cauldron on to heat while she fetches supplies from the cupboard. She knows not to begin preparing ingredients until Professor Snape arrives, and she glances at the clock once more. It's a minute past. He should be here by now. Surely he hasn't forgotten.

Hermione stops fiddling with the ingredients and walks to the door, where she looks out into the corridor. Her heart nearly stops when she sees him lying face down on the floor. 

She rushes to his side and finds him barely conscious, his thin lips turning blue, and his breathing fast and shallow. Merlin on a Mooncalf, she started heating the potion before he had the Bubble-Head Charm in place!

She casts the charm quickly and shakes his shoulder. 'Professor Snape? Professor? Are you all right?'

He makes to look at her, but his head lolls to the side uncontrollably. He moans inarticulately, and there's white froth at the corner of his mouth.

She has to get him to the hospital wing. She Levitates his body into the classroom, removes the cauldron from the fire, grabs a handful of Floo Powder from the desk and casts it into the flames.

Madam Pomfrey is de-hexing a couple of first years but springs into action when Hermione brings Professor Snape through the fire.

'I found him like this in the hall. He was just lying there. I think it's because I started warming the potion before he got to the classroom and the fumes reached him before he had a chance to cast the Bubble-Head Charm, and I tried to wake him and—'

'Hush." Madam Pomfrey's voice is gentle but firm. She dispels Hermione's Bubble-Head Charm with a wave of her wand and bustles to the medicine chest to retrieve two phials. 'I warned them this would happen. But men will always play with fire.' She shows Hermione how to hold his head back as she pours a crimson potion down his throat, followed quickly by a green one. 'Don't worry, child. The first will settle the shock, and the second will make him sleep. He'll be right as rain in the morning. Now, back to the dungeon with you. I've things well in hand, and there's no sense in ruining that batch of Wolfsbane.'

Hermione is momentarily taken aback that the matron knows about the project when the Headmaster swore Hermione and Professor Snape to secrecy. But Madam Pomfrey clearly knows what ails Professor Snape, so perhaps she's treating his lycanthropy as well. She turns to go but stops as a wild idea occurs to her. 

'Madam Pomfrey,' she says, not having to feign the uncertainty in her voice, 'Professor Snape was bringing me a book. He said it would help me understand the last stage of brewing—' 

The matron briskly pats Professor Snape's robes, reaches into his waistcoat pocket, and pulls out a Shrunken volume with a peacock blue cover. Hermione holds her breath as she squints at the tiny print.

'Is that it?' she asks, handing it to Hermione. 'My eyes aren't what they once were, I'm afraid.'

'That's it.' She hopes the matron doesn't hear her voice shaking.

'Good. Off with you, then. And be a dear and bring the Wolfsbane up when you're finished.'

'I will,' says Hermione. Inspired, she adds, 'Since I'm brewing alone, it may take a bit longer than expected.'

'Well, if I've gone to bed by the time you finish, the potion should be safe here.'

'Thank you, Madam Pomfrey. I expect it will be.'  


~o0o~

Lucius Malfoy's library is not what she is expecting. She imagines something like the restricted section of the Hogwarts library, but instead of dark, cramped shelves filled with chained and bloody books, she finds herself in a bright, airy room with dozens of floating shelves that move gently aside to admit her. Light pours in from a trio of mullioned windows that overlook the bridge.

She is surprised that his library is at least as well organised as her own, easily a hundred times as large, and infinitely more valuable. There are books bound in gold with precious jewels, books bound in carved wood and stamped leather, books containing fiction, drama, a hundred different dictionaries, scholarly works—everything. She can't help but wonder if he's bothered to read any of them. Her fingers itch to touch them, but she knows all too well how dangerous Malfoy's books can be. Steeling herself against temptation, she emerges from the shelves and finds Lucius and the man with the white whiskers taking tea by the fireplace.

'Hermione, how good of you to come,' says Lucius, rising and giving her a warm smile. 'Allow me to introduce Laurence d'Aubigny.'

Hermione's eyes widen in surprise. 'Laurence d'Aubigny of the _Centre National de la Recherche Magique_?'

'Yes. And you are Hermione Granger of St. Mungo's, I think." He rises to take her hand. His voice is slightly scratchy from his earlier ordeal, but it's a warm baritone, light and charmingly accented. 'I apologise that you took me by surprise earlier. I did not know that you and Lucius were acquainted.'

Hermione glances at Lucius, whose face betrays nothing as he conjures a third chair for her to use. Clearly, he has no interest in correcting d'Auigny's assumption that she is on social terms with him, and she's certainly not going to, not when it affords her the opportunity to pick the brain of one of the most brilliant magical theoreticians in the world.

'Hermione was telling me about her research earlier,' says Lucius. 'I imagine you'd find it quite interesting.'

'More work on magical sensitivities? The data you published in _Proceedings_ caused an uproar at the Sorbonne.'

'That's only because Jacques Thique is convinced that the patient's response is caused by a mutation in the allergen, not that he has any evidence that's what's happening.'

There is something familiar in the way d'Aubigny twists the tip of his moustache. 'And you have?'

'Nothing that demonstrates causation.'

'But a correlation?' d'Aubigny's dark eyes dance beneath white brows.

She can't help smiling. 'Yes. We've discovered a novel by-product of magical decay, just as your article in _Magic Today_ predicted. We've conclusively linked it to patients experiencing a magical sensitivity.'

' _Magnifique_ ," he says, eyes glowing. 'Have you detected it anywhere else?'

'Not until today, unless I miss my guess,' says Lucius, sipping his tea.

d'Aubigny gives her a knowing look. 'Ah. The reason for your visit, I think.'

'Hermione's visit is every bit as welcome as it was unexpected.'

She manages to turn an indelicate snort into a cough. 'Regardless, you'll be reading all about the particles in November's issue of _Theoretical Magic_. That is, if we ever decide on nomenclature.'

Malfoy cocks an eyebrow at her, but d'Aubigny chuckles. 'Stumpf wants to call them something incendiary?'

'I wanted to call them thaumatons, since they seem to be a fundamental magical particle of some sort. But the editor thinks it's too esoteric and asked for something sexier. I told him to call them Merlin particles.'

This startles a laugh out of both men.

'What did the editor say?' asks Lucius.

'He said he'd sleep on it. It's been a week since then.'

'If he is sleeping on it for a week, then it's definitely sexy enough, _n'est-ce pas_?'

It's Hermione's turn to snicker. She has a moment of imbalance at the surreality of having a laugh with Lucius Malfoy and a department head at CNRM.

'I certainly hope so,' says Hermione. 'The whole thing is so silly. I theorised their existence and isolated them from samples taken from patients. I should be able to call them Ethelreds if that was my fancy. Getting away from that mess is the reason I decided to go on holiday, actually. Not that it has led to a detectable reduction in my stress level.'

'I am well versed in the art of attempting to get away from it all and failing,' says Lucius.

Hermione suspects that he's talking about more than her holiday.

'How did these particles bring you to Lucius's party?' asks d'Aubigny. 

She explains about her watch and shows it to him, and his face grows thoughtful. Her eyes are drawn to the deep creases between his eyebrows and at the corners of his mouth, which are in sharp contrast to the smooth skin in his cheeks. Despite his shock of white hair and old-fashioned facial hair, he isn't as old as he appears. And yet, the scars suggested by the irregularities in his whiskers suggest that he has seen much of life. 

Having read d'Aubigny's entire academic output, she has long admired him for his ability to turn accepted scientific paradigms on their heads. She isn't surprised to find that he is every bit as witty and clever as his writing would suggest, and yet, it's the suggestion that his life has been more than just of parties with the moneyed intelligentsia. She feels a thrill of excitement that he is listening to her so intently and is, to all appearances, as interested in her work as she is in his.

His lips are pursed his lips in thought. 'These Merlin particles. You say they are a by-product of magic breaking down. Have you tested for them in other circumstances under which a similar breakdown of magic is believed to occur?'

Hermione smiles. One of her anonymous peer reviewers asked the same question. She wonders if it was d'Aubigny. She gives him the expected answer. 'It's a set of experiments I'd like to conduct at some point in the future, but I'm afraid it's well beyond the scope of my current project.'

'If I may be so bold,' says Lucius, 'I might suggest that you're investigating that at present.'

Hermione looks at him sharply. He's right. Clearly, nobody in the house is currently suffering from acute magical sensitivity. So why are the Merlin particle levels so high? She allows her gaze to travel back and forth between the two of them, trying to figure out exactly whose idea it was to invite her and for what purpose. 

Lucius smirks, as though reading her thoughts. 'I consider it to be a privilege to contribute to the greater good however I may. You may of course have free run of the house.'

'And I am as intrigued by the puzzle as you are,' d'Aubigny says.

'I daresay Laurence and I are at your disposal. I do hope you will use us as you see fit.'

His purring voice shakes Hermione out of her complacency. She should leave. She should go back to England and forget it all. Instead, she finds herself returning Lucius's languid smile. 'I'm certain I'll be able to find something for you to do.'  


~o0o~

The book! The book is hers! The rush of triumph sings in her ears as she races down the stairs to the dungeon with the precious Shrunk object clasped tightly in her hand. She rushes into the empty classroom, locks the door physically and seals it magically behind her, and stops to catch her breath and focus.

The Wolfsbane. She must complete the Wolfsbane, otherwise the plan falls apart. Professor Snape will figure it out. But she can read a few pages now. She can read during the numerous breaks while the potion simmers. She can read when the potion is complete for as long as she dares. But only if she can trust herself to stop in time to return the book to the hospital wing before Professor Snape wakes.

She puts the still-warm cauldron back on the burner and tosses the hawthorn blossoms in. The next steps must be done precisely, or the potion will be too sludgy to absorb more dry ingredients. She reaches into her bag and pulls out the Wolfsbane journal, which she places on the bench next to the purloined volume. When the petals turn purple, she sets her timer for fourteen minutes, Enlarges the blue book and opens it.

It does not disappoint. The first chapters introduce the main characters and their taste for rapaciousness, violence, incest, abductions, and philosophical libertinage. There is also a description of a cock so enormous that Hermione has to estimate against her arm to make sure she has read it correctly. The protagonists are all despicable and cowardly, and yet the narrator treats them with the same affection as he gives the reader.

_And now, friend-reader, you must prepare your heart and your mind for the most impure tale that has ever been told since our world began, a book the likes of which are met with neither amongst the ancients nor amongst us moderns._

Hermione swallows hard and glances at the timer before reading on. A new section begins on the next page, but she really ought to stop here. But her greedy eyes seek the last few paragraphs.

_Many of the extravagances you are about to see illustrated will doubtless displease you, yes, I am well aware of it, but there are amongst them a few which will warm you to the point of spending, and that, reader, is all we ask of you; if we have not said everything, analyzed everything, tax us not with partiality, for you cannot expect us to have guessed what suits you best. Rather it is up to you to take what you please and leave the rest alone, another reader will do the same, and little by little, everyone will find himself satisfied. Choose and let lie the rest without declaiming against that rest simply because it does not have the power to please you. Consider that it will enchant someone else, and be a philosopher._

She feels a flare of irritation when the timer goes off. She reluctantly lays the book down, which proves to be fortunate, since tendrils of not-quite-cobalt steam are rising from the surface of the potion. She pushes the reprehensible libertines and their chosen perversities from her mind and turns once more to her Wolfsbane notebook.

She steals a few more chapters in the six minutes between stages and is fascinated by the prostitutes the protagonists have hired to inflame their passions by telling stories from their lives. The stories very quickly becomes disgusting, and if not for de Sade's plea to take what she likes and ignore the rest, she might consider stopping.

Before long, the potion is finished, and Hermione seats herself at the desk, since the chair is much more comfortable, and reads as fast as her eyes will let her. This is partially because she knows she must return the book to Professor Snape and partially because there are long sections devoted to activities that are not just unsexy but make her feel queasy, She hopes to forget about them as soon as possible.

Having borrowed more than a few bodice-rippers from Parvati Patil's collection, she finds it interesting to read something from a male perspective, especially a male attempting to defend the indefensible. She is amazed and slightly horrified how easy it is to slip into the libertines' perspective, imagining ways to use the harem members in line with the day's story. It makes her feel a bit dirty, to feel fascinated by de Sade's audacity even as some of the individual elements disgust her. There's an elegance of form and structure to their libertinage, and she watches it unfold, aghast but unable to look away.

She suddenly realises that she needs to use the toilet, and she sees that it's very late — far later than she had thought. She's less than halfway through the book, but she must stop. She Shrinks the cauldron, seals the lid, and ducks into the girls' toilet.

While she is not typically the type to dawdle, she opens the book in the stall. She skips the rest of the simple perversions, the majority of which are truly disgusting, and skips about in the more horrific chapters. It's a bit about chopping off fingers that finally disturbs her into closing the book, and she Shrinks the book to prevent her reading further. 

The hospital wing is empty except for Professor Snape. She places the cauldron by the medicine cabinet and approaches him. The matron has certainly gone to bed, and she has left Professor Snape recumbent, his arms at his sides, breathing slowly and evenly. She moves aside his teaching robe and slips the Shrunk book into his waistcoat pocket. She absently smooths the black and dark grey brocade with her hand before backing up. 

His breathing has not changed, and Hermione breathes a sigh of relief. She crosses her arms, wrapping her robes against herself tightly, and tiptoes out of the infirmary.

She does not see him open his eyes.  


~o0o~

Hermione feels a bit like Basil Rathbone's Sherlock Holmes swishing about Malfoy's chateau looking for clues with her wristwatch. The west wing yields no clues, and she sees no variation in residue levels until she comes to a nondescript door off the kitchen. A wave of mauve sweeps across the dial so quickly that she wonders if she's imagined it. She seizes the handle and pulls, but the door is locked.

'Batty, what's in here?'

'The pantry, Miss,' squeaks the elf. 

'May I see it?'

He waves his hand, and the door swings obligingly forward. The pantry is cool, lit only by a single glowing sphere. It's filled with fresh vegetables and fruits, cheese, and a few preserved meats. It's difficult to see the dial in the low light, but it's definitely a lighter shade of purple. Feeling somewhat foolish, she waves her arm near the potatoes on the high shelf and the successively lower shelves. She is rewarded by another tendril of purple when she passes an enormous wheel of cheese balanced on its edge on the pantry floor.

She frowns. It makes no sense that cheese should exhibit magical decay. She takes a step towards the cheese to examine it more closely, when a floorboard squeaks under her foot. 

Of course. All the floors in the chateau are stone. The particles aren't coming from the cheese, they're coming from what's beneath the cheese. She rolls the cheese to the back of the pantry and clears the space around it. The weight of the wheel has raised the corner of one floorboard, and she prises it upwards. She kneels on the floor and lights her wand to look into the empty space beneath.

There's a stone staircase leading down into blackness. She glances at her watch and when the face blooms mauve, she decides to go on alone. A glance confirms that the kitchen elves aren't paying her the least bit of attention, so she closes the pantry door and pulls up enough floorboards to admit her. She slides between the crossbeams and climbs down the steps.

The staircase is square, and each flight comprises eight steps. The air is damp and cool, and she wonders if she is climbing down into the bridge's support structure, past the waterline. At the bottom of the eighth flight, there is a narrow passageway. Outside the range of her wandlight is utter darkness. She comes to an archway that reveals a rectangular room about the size of her flat's bedroom. In it, ten empty bed frames are pushed together, and ten chamber pots are stacked haphazardly by the door. Perhaps this was where men-at-arms were once quartered?

There is nothing else in the room, so she continues onward. She passes another similar sleeping quarters and walks until she arrives in a large room with four alcoves radiating outward from a raised dais. At the back of each alcove hangs an ancient, rotting curtain.

A cold feeling settles in Hermione's stomach. Something about the cruciform room feels ominously familiar, and before pulling back the curtain, she knows what she will find. It's a bedroom, but from the ceiling hang chains, and surrounding the bed are objects whose use she does not wish to imagine, including a brazier for heating them until they glow red. She feels the triumph of recognition, which is quickly followed by revulsion.

She knows this place. She read about it in a book eighteen years ago. This place is the product of prodigious imagination twisted by bitterness and entitlement into something monstrous. This is a place that has seen torture, rape, and murder. This place should not be real. 

She returns to the cruciform room and stands on the stone dais, where the day's storyteller would have regaled the company with tales of licentious behaviour. On the one hand, she is horrified that the fictional world she allowed herself to revel in once actually exists and may have actually been used to host the kind of ghoulish gatherings de Sade wrote about. On the other hand, her cheeks grow warm as she imagines herself as the experienced woman with the ability to tell a story that arouses the listeners and spurs them to greater heights of villainy. She hasn't experienced the sorts of things that inflamed de Sade's libertines, and frankly, she's glad of that. But she has known suffering and cruelty, and on this subject she could speak at length. She gazes down at the alcoves where the libertines sat, and she imagines that they would be delighted by her words.

She nearly falls off the dais when she notices Lucius Malfoy watching her from the room's entrance.

'This place is familiar to you?' he asks.

She wills her hands to stop shaking. 'Yes.' Her voice sounds flat to her own ears, but at least it is steady.

He gives her an infinitesimal nod. 'It was built by my great-great-uncle thrice removed. I don't believe it's been used since his time.'

'Your great-great-uncle thrice removed was an admirer of the Marquis de Sade, I take it?'

'In a manner of speaking. He was the Marquis de Sade.'

Hermione knows better than to act surprised when she is not.

Malfoy enters the chamber and sits on the step leading to one of the four alcoves, where the mastermind of the ritualistic tableaux would have sat. And yet, he sits beneath her, as though she controls the situation. Even now, she knows she does not, any more than an actor controls the audience. She is alone with Lucius Malfoy in his own dungeon, armed only with her wand, which she dares not extinguish to cast any spells. Her fingers unconsciously dance along her collarbone, where a thin scar serves as a reminder of the last time she was in Malfoy's home. 

She takes a deep breath, and meets his eyes. 'Is there more?' she asks, gesturing to the room. 'The punishment chamber? The banquet hall? The parlour?'

'There is no need for a separate dining hall when there is a perfectly serviceable one upstairs.'

Her lips quirk at the half-answer. 'And the rest?'

'Would you like to see it?'

She glances at her watch, which is fairly pulsing with red. 'It seems that I must.'

He rises, approaches the dais, and offers her his arm. 'Then it will be my pleasure to show you.'

She puts her hand on his forearm and allows her to lead her from the dais back to the corridor. That she's glad for his company and the warmth of his arm disturbs her nearly as much as the rooms they tour.

~o0o~

After returning the book to her unconscious professor in the hospital wing, Hermione sticks to the shadows on her way back to Gryffindor tower, narrowly evading Peeves, who is singing a rude version of Old Hundredth at the top of his lungs while riding the banister of a moving staircase, and Mrs Norris, who sniffs the entrance to an alcove whose curtain is rippling suspiciously.

She whispers the password to the Fat Lady, who feigns being asleep until she shoots sparks at the canvas. The portrait swings forward with an audible huff, and Hermione dashes up the stairs and pauses to catch her breath before opening the door to the dormitory as quietly as she can. She is relieved to find her room-mates asleep, and she ducks behind the curtains of her bed.

She's barely closed her eyes when one of the scenes from the book appears in her mind's eye — one of Duclos's tales from the monastery, and she pictures Professor Snape instructing her in the best way to please him in his classroom voice. Her hands are between her legs in an instant, and she frigs herself to climax in seconds. As she lies there, her intimate places pulsing in time with her elevated heartbeat, she stubbornly refuses to think about the broader implications and surrenders to sleep. Of course, her subconscious cannot ignore it, and she tosses and turns as Professor Snape's voice harangues her for her dishonesty. When he appears before her and backs her against the Potions bench, she knows she deserves everything she gets and surrenders to his punishing mouth. She feels like a rag doll, being tossed from side to side as his mouth devours her, teeth nipping and tongue twirling.

She cries out, and the shaking becomes more insistent. She jerks into wakefulness to a pair of concerned brown eyes.

'All right, Hermione?' asks Parvati. 'Nightmare?'

Hermione nods wordlessly, still breathing hard.

'Lavender had one last night, too. Must be the full moon tonight. Anyway, you'd better hurry. Breakfast is in ten minutes.'

'Oh!' Hermione is shocked how late she's slept. 'Thanks, Parvati.'

She splashes water on her face and makes an attempt to brush her hair before giving up and twisting it into a messy bun. At breakfast, both she and Harry receive mail addressed in the Headmaster's script. Judging from the eager determination in Harry's eyes, he has another special lesson tonight. Encouraged, Hermione opens her letter.

_Dear Miss Granger,_

_Thank you for your excellent work on your special project. However, circumstances are such that it has come to an end. I have taken the liberty of returning your house's point total to the amount it had before yesterday's session and hope you will consider this will be sufficient thanks._

Hermione tries to ignore the sinking feeling in her stomach. The twenty-five points that Professor Snape subtracted on the second night of brewing is a pittance to someone as free-handed with them as the Headmaster. How many points must Professor Snape have deducted? She risks a glance at the head table and finds the object of her thoughts glowering at her from behind his curtain of hair. She nearly faints with relief to see that he is no more irritated with her than usual, so the excessive penalty is for nearly killing him with Wolfsbane fumes, not for borrowing a contraband book. Her secret is safe.

She tries to look contrite, but the narrowing of his eyes makes her aware that he isn't fooled. She takes one last sip of tea before fleeing to Charms. 

It's not until later that she recalls Parvati's words about the full moon that night. Yet Professor Snape looked perfectly normal at breakfast.  


~o0o~

When Hermione and Lucius return to the library, d'Aubigny is bent over a large scroll written in French examining it through a pair of pince-nez. He looks up at them over the black frames.

'You have found what you were looking for?'

'I went looking for an answer,' she says, sitting. 'I found a mystery.'

'This is usually the way of things,' says d'Aubigny, with a wry smile that makes his eyes crinkle winsomely at the corners. 'Come, _ma petite_ , I wish to show you something. You do read French, do you not?'

'Read? _Oui._ Speak? _Comme ci, comme ça_.'

'It will do. Look, if you will, here.'

_'Clarify, if you will,' said the Duc. 'What is in this glorious concoction?'_

_'I do not know all, my lord,' replied Martaine, 'merely that it was turquoise in colour, smelled of juniper, and the primary ingredient was mandrake that had been ruined by rot. The recipe probably died with the apothecary.'_

_'It is not so,' said Curval. 'For that same apothecary came before me for some fatal error in brewing, and he offered his secrets in exchange for his life. I took his recipes and had him hanged. This particular potion is difficult to brew but produces the most delightful dampening of magic so that one may take a wizard or witch as easily as a Muggle without fear of accidental magical discharge.'_

_'Oh let it be made quickly,' exclaimed the Bishop. 'For my prick is hard and I wish to put it inside Zelmire, but she is protected by the power she knows not yet how to wield, and I do not desire scorch marks on my bum such as those the Duc received upon her posterior deflowering.'_

'Good Gaia!' Hermione is utterly gobsmacked to see the original text of '120 Days of Sodom' in de Sade's own handwriting.

He gives her a shrewd look. 'You are offended by the contents?'

'No. I've read it. Most of it, anyway. Years ago.'

'If you will forgive the familiarity, but I suspect you rarely leave books unfinished."

His gaze is piercing, and she feels compelled to answer with the truth. 'I hadn't yet reached my majority at the time, but I borrowed a copy for a few hours.'

'One wonders from whom a Hogwarts student of Muggle parentage obtained it,' said Lucius, regarding her with curiosity rather than hostility. She is pleased to note that there is no scornful inflection on the word 'Muggle.'

She meets the men's eyes in turn, grey and deep brown, and feels the storyteller's mantle settle on her shoulders. Though it's a story she's never shared with anyone before, the details are clear in her mind, and it spills forth almost of its own accord.

'In my sixth year, I was given a special assignment by the Headmaster. It was overseen by one of my teachers, and I saw him reading the book.'

'He made no attempt to hide it?' asked Lucius.

'He didn't wave it about, but I spotted the title almost by accident. I was so surprised I broke two fingers with a pestle.'

'You had the presence of mind to take the book then?' asked Lucius.

'Oh no, I stole it when he was ill, but I had to return it before I finished.'

'So you have no idea what happens in the end?'

'I know enough from the Muggle version.'

'Were you never curious to finish the magical version?' asks d'Aubigny.

'My dear man, copies are difficult to obtain in England and quite dear. The teacher in question was our dear departed Severus, was it not?'

Lucius's mocking tone sets Hermione's teeth on edge. 'You assume a great deal.'

'Not at all. You see, it was my own translation that Severus was reading. Goodness, what you must have thought of him!'

Hermione recalls the incendiary dreams she had the night after reading the book. 'It was most educational.'

Both men smirk at that, but Hermione's eyes linger on d'Aubigny's. It's remarkably wicked, despite the avuncular whiskers.

'As fascinating as these reminiscences are,' says d'Aubigny, smoothing his moustache, 'my purpose in showing you this passage is to perhaps explain what you have seen here.'

Lucius examines the scroll where d'Aubigny indicates. 'You believe this potion caused the anomalous readings?'

'It temporarily drains a wizard of magic. This is similar to the effect Hermione has described when a wizard is in contact with a magical allergen, non?"

'The spoilt mandrake is suggestive,' says Hermione. 'Mandragora is a powerful restorative, but when combined with its fungal antithesis, it has been known to produce the opposite effect, though never predictably enough to use in a potion.'

As d'Aubigny explains to Lucius the finer points of magical rots, Hermione considers the presence of the Merlin particles. Having determined that Lucius is not hiding a host of ill witches and wizards in his dungeon, nothing remains but to determine the source of the particles, and d'Aubigny's explanation is simple and elegant. Still, to consider that de Sade actually made the potion and used it on people — it's nearly as troubling as her own disappointment that she no longer has an excuse to trespass on Lucius's generosity. She chooses not to think further on either subject and returns her attention to her companions.

'But that would make the potion toxic, wouldn't it?' asks Lucius.

'Of course, but you forget that nearly all potent ingredients are poisonous in large amounts. But if we use vanishingly small amounts, such as belladonna or holly berries, they become medicine, _n'ecst pas_?'

'That's it!'

Both men's heads snap towards her with twin looks of surprise, and she fights the urge to giggle.

'Medicine. Or rather, treatment. What if we used de Sade's magic dampening potion to treat people suffering from magical allergies?'

Lucius frowns. 'Wouldn't that simply result in a faster drain of power?'

'The book doesn't say anything about the potion draining wizards to the point of illness or death. Surely if that were a side effect, Curval would have said so. Besides, everything depends on the dosage.'

'You are of course assuming we will be able to re-create de Sade's potion from this manuscript. If it even exists.'

'De Sade has detailed notes for a number of unknown potions in his journals,' says Lucius. 'I can have the elves cross-reference the description from the book against his other papers.'

'You use house-elves for research?' Hermione can't decide if she's horrified or envious.

'It is a tradition at CNRM,' says d'Aubigny. 'Though we must use first year apprentices because we are unable to attract elves.'

Hermione grins and catches d'Aubigny's eye. His lips are thin and his teeth are uneven, but they do not detract from the winsomeness of the smile he gives her. 'Your enthusiasm is as contagious as it is charming, _ma petite_. I must return to Paris on Sunday night, but you may lay claim to the rest of my Saturday and the first half of my Sunday.'

'Monsieur d'Aubigny, I don't know what to say.'

'First, say 'Laurence,' he says with feigned sternness. 'Secondly, say ' _Merci_.''

' _Merci beaucoup_ , Laurence.'

'Thirdly, you may say, 'Lucius, I would be proud to give you and your unparalleled collection an acknowledgement in the series of papers d'Aubigny and I will be co-publishing.''

d'Aubigny snorts, and Hermione parrots Lucius's words with a saucy toss of her hair.

'And fourthly,' says Lucius, 'You may offer me your cheek.'

Too surprised to do otherwise, she turns her face to the side as Lucius leans forward and brushes his lips against her cheek.

Utterly flummoxed, Hermione feels the blood rush to her face. Fortunately, Lucius doesn't seem to require any response.

'I'm afraid I'm being a negligent host to the rest of the guests,' he says, regret audible in his voice. 'But they will be trickling out once we've had afternoon tea. Minny, Batty, and Wimsey are at your disposal. Wimsey trained at Cordon Bleu, so his knife skills are exemplary, and all three may be trusted to prepare ingredients should you attempt brewing later.'

'As ever you are generosity personified, _mon ami_.'

Hermione hears an odd mix of exasperation and humor in d'Aubigny's voice. 'Thank you, Lucius.'

His expression is momentarily surprised as he registers the warmth in her voice, but he quickly covers it with a polite smile as he disappears into the floating bookshelves.

She turns toward d'Aubigny, who is smirking.

'I see my friend possesses exquisite taste,' says d'Aubigny.

'I think he's trying to keep me off balance,' says Hermione, willing herself not to think of Lucius's lips on her cheek.

'The two are not mutually exclusive, _cherie_. You know he has been separated from his wife for many years, no?'

'Laurence, I don't know how much you know about the conflict that took place in England almost twenty years ago, but let's just say that Lucius and I were on opposite sides. He and his colleagues did unspeakably awful things to me and my friends.'

'Would Lucius not say that you and your friends did unspeakable things to him and his?'

Hermione laughs. 'It would be most impolitic of him to say so, considering our side won. Besides, I suspect Lucius suffered more from his sworn master than from us.'

'If what you say is true, why then did he not stay in England?'

Hermione sees what d'Aubigny is implying, but keeps her voice light. 'I suspect you have greater insight into his motives than I do. I barely knew the man and haven't seen him in twenty years.'

' _Touché_. It is true, the Lucius I know and the Lucius you knew are likely to be very different. I hope you will be able to reconcile yourself to this version. He can be _tres agréable_ when he has a desire to be so.'

'I'll consider it,' she says, surprised that she is not simply pacifying the old meddler but speaking the truth. 'However, his timing is terribly inconvenient. I hope you will not be shocked that I'd rather spend my limited time with you.'

His eyes twinkle like a cat's. 'Surprised, _certainement_. But displeased? Not at all.'  


~o0o~

The morning after the full moon, Hermione is shocked and a little bit disappointed to see Professor Snape at breakfast looking like his usually dour self. In fact, he looks better than he did the day before, though that's unsurprising, given that he spent the night in the hospital wing. She knows that apart from her use of mint, the Wolfsbane was no different than the previous batch. Either Professor Snape is not a werewolf and his ill health was due to something completely different, or he's a far better actor than she ever gave him credit for. Neither explanation is wholly satisfactory. The latter is downright disconcerting.

Scenes from the book dance in her mind's eye as she finishes her toast, and she ponders anew why he would read such a thing. She dismisses idle curiosity out of hand. After being a Death Eater for over a decade, surely he has nothing to learn about cruelty. She smiles to herself. His teaching methods are proof positive of that. And surely if his sexual proclivities were any concern, he wouldn't be allowed to teach. Even Professor Dumbledore wouldn't be that desperate, would he?

Then again, the Headmaster allowed three children to face the protections surrounding the Philosopher's Stone, not to mention someone under Voldemort's influence. He managed to be wholly absent from the school when the Basilisk was on the loose. He refused to intervene the night Sirius was almost given the Dementor's Kiss, short of suggesting that she use the Time Turner if she wished to do anything about it. If Professor Snape is the Headmaster's only spy in Voldemort's camp, then he must have a great deal of leeway regarding his behaviour.

But the book—surely he knew she would be curious. He practically waved it under her nose and dared her to read it. The memory of his fury the night she commented on it makes her shiver. As he rises to leave, she wonders if he has the book with him.

During Defence, she fancies she sees the shape of it in his waistcoat pocket and is possessed with the wild desire to set some aconite afire in his vicinity and steal the book from him again, but she knows she'll be caught. Now that she's no longer brewing with him, that window is closed. She resolves to read the Muggle version of the book as soon as she can get her hands on it.

She glances at Ron, who is whispering with Harry about Quidditch. Despite their initial misunderstanding, she's quite looking forward to taking him to Slughorn's party. She wonders if he has any expectations about what they'll do afterwards. And if he has, she's fairly certain that she won't object. That is, if Professor Snape doesn't ban him from the party for drawing play diagrams on the back of his essay.  


~o0o~

d'Aubigny is quiet as they read, but when he does speak, Hermione listens. His voice is as pleasing to her ear as his comments are to her mind. Lucius is still away charming his guests, but he sends Batty with a tray of sandwiches and tea. d'Aubigny is poring over the manuscript and Hermione is elbow-deep in de Sade's journals, household books, and diaries. She is surprised by some of the personal reflections, particularly those after the Reign of Terror. Apparently, the man who murdered for his own pleasure and gain was considerably more squeamish about a political movement doing the same. Perhaps it was the idea that strict ideals could be every bit as immoral as libertinage.

'You see something _amusant_ , Hermione?' 

She speaks her thoughts aloud and d'Aubigny nods thoughtfully. 'I think this is a key to understanding the man. Indeed, it is one thing to espouse a belief in principle. It is another thing entirely to have it brought home.'

She doubts d'Aubigny is speaking only of the Marquis and briefly wonders how long d'Aubigny has known Lucius.

At last, the cloud cover begins to break up, and Hermione is struck by d'Aubigny's profile against the sunlit window. The light renders his white whiskers translucent, and she can examine the shape of his face. The profile is all angles, save for the great curve of the nose, and Hermione appreciates the way his whiskers soften the sharp planes. She doubts his face would have the same kind of avuncular charm without them. And yet, she imagines it would be an arresting face, one that has no trouble commanding authority.

Belatedly, she realises d'Aubigny is speaking. She starts, and he smiles gently at her. 'You are lost in thought?'

'Not lost—deliberately exploring.'

' _Mais oui_ ,' he says. 'Then do not let me stop you exercising your little grey cells.'

Hermione smiles, and d'Aubigny returns to his work. She is grateful that d'Aubigny is bent over the manuscript when the familiar words hit home. Little grey cells. She resumes her perusal of his face, when he takes a nearby book and props it up on the spine of another book. He licks his finger before gently separating two layers of paper — a gesture that resonates in her memory nearly as much as the words. A line forms between his eyebrows, and suddenly, Hermione knows. She knows him by his gestures and by the shape of his hands. She knows his current persona to be a façade, though opposite of the one he presented when she knew him last.

'Laurence, have you read any Agatha Christie?'

He looks up, to all appearances confused by the abrupt change of topic. 'She is one of your English authors, yes? Quite famous?'

'Yes. She wrote detective stories. You just used one of her characters' famous catchphrases, and I wondered.'

'Ah! You speak of Hercule Poirot. Many years ago, I saw a film in a Muggle cinema about a murder on a train. I think it was there that I met the Belgian and his 'little grey cells.''

The explanation is simple, direct, and has the ring of truth. And yet, now that Hermione is listening for it, she knows it's not the entire truth. Her mind is abuzz, and she has no idea how or even if to broach the subject. She eventually decides that saying nothing is the most prudent course of action and returns to the journals, especially when there is work to be done. However, she can't help but steal glimpses when he isn't looking, and can feel the familiar buzz of excitement at his proximity.

The sun is low in the sky when Lucius returns to the library. 

'At last, my home is my own once more,' he announces, sinking dramatically into one of the armchairs by the fire. 

d'Aubigny raises an eyebrow at him. 'It was not before?'

'Can a place inhabited by intolerable bores be truly mine?'

'You invited them, didn't you?' asks Hermione.

'Of course, but I did so as a courtesy.'

'Never social-climbing,' says d'Aubigny.

'There is no need to make vulgar accusations simply because I have the manners to return hospitality,' says Lucius. 'In fact, I can't recall ever having received an invitation to visit Chez d'Aubigny.'

d'Aubigny doesn't look put out in the slightest. 'I fear I would be unable to entertain you in the manner to which you are accustomed, _mon ami_. I am a man of simple tastes.'

'So says the man who polished off a whole pheasant and a plate of _fois gras_ at supper last night,' says Lucius to Hermione in a stage whisper. 

d'Aubigny looks down his nose at Lucius. 'I make no claims to asceticism.'

Lucius smiles at him fondly. 'Thank Merlin for that. You'd be even more insufferable, else.'

Where Lucius's romantic attentions unsettle her, his good-natured ribbing elicits genuine laughter. She will always carry with her the memory of being assaulted in his home, but she is confident that she has nothing to fear from this Lucius. 

For his part, d'Aubigny's mouth twitches, and Lucius claps his hands. A bottle of champagne appears in front of him with three glasses. He waves his wand and Vanishes the cage and foil, but to Hermione's surprise, he opens the bottle by hand. The contents give a soft hiss as he gently draws out the cork.

He hands Hermione a glass with an endearment in French and offers one to d'Aubigny. 'I apologise for not offering you water but hope this will suffice.'

The bubbles are exquisitely fine, and Hermione catches a whiff of creamy crispness.

Lucius raises his glass. 'To old friends and delightful new acquaintances.'

d'Aubigny follows suit. 'To discovering the undiscovered.'

Hermione touches her rim to both of theirs. 'To Severus Snape.'  



	3. Chapter 3

When the last of the dummy Inferi lies in a smouldering heap on the floor, Professor Snape dismisses the Defence class with only a modicum of threatening. Ron and Harry make a beeline for the door, but Hermione lingers. Professor Snape is obviously aware of her presence, but he makes a show of marking essays. She stands at a respectful distance and waits.

Finally he sighs loudly and lays his quill aside. 'What do you want, Granger?'

'I just wanted to apologise—'

'I'm sure you do. Can you think of any reason that I should allow you the privilege of doing so?'

She isn't certain how to respond to this. 'You should hear me out because it's the only way you'll know exactly what I did.' 

Her last words lilt up interrogatively, and the effect on him is electric. He slams his palm on the desk with enough force to dislodge two homework scrolls from the pile and send them tumbling to the floor. 

'You seem to be under the mistaken impression that you know something I do not. I assure you, Miss Granger, not only do I know every one of your actions that occurred in my vicinity two nights ago, but I would be willing to wager that I know what you did afterwards. The Headmaster may have blocked my attempts to punish you for your flagrant disregard for safety, but if he were to know of your felonious proclivities, you would certainly be expelled. I refuse to grant you any more unearned privileges. You will have neither the opportunity to apologise nor to atone. Should you attempt to speak to me again about anything unrelated to the subject I currently teach, I will assign you detention with Mr Filch. Now remove yourself from my presence before I lose my temper.'

Hermione's heart is beating a tattoo against her ribcage. 'If you tell the Headmaster, you'll have to tell him which book it was.'

He sits back in his chair, rather like a cobra coiling to strike. 'I hope I misunderstand your purpose in asking that question. Because if I do not, attempted blackmail is an even more serious offence than stealing and reading an age-restricted book.'

'I just thought you wouldn't want the Headmaster to know—' she can't say it.

He crosses his arms. 

'That you're—' The words catch in her throat again. 'That the book holds appeal for you.'

He looks at her for a long moment and raises his chin. Though he's sitting, she feels as though he's towering over her. She wants to look away, but his dark eyes are glittering dangerously. 'Considering your increasingly reckless attempts to lay hands on the book, I should think that your own interest in it would be of greater interest to the Headmaster. Or perhaps your little boyfriend?'

Hermione's cheeks flush scarlet.

'I confess myself surprised at you, Miss Granger, for all that I shouldn't be,' he continues, his voice like frozen velvet. 'I knew the company you kept was unfortunate, but I hadn't grasped the thoroughness with which you've been indoctrinated into their hypocrisy.' 

Her thoughts are a jumble. She opens her mouth to protest, but there are no words. Her silence seems to inflame him further. He leaps to his feet, rocketing his chair back into the chalk rail of the blackboard. His eyes feel as though they're boring into hers. 

'You dare to judge me for reading a book that you yourself have begun reading and ardently desire to finish? Are you so lacking in perspicacity that you cannot think of a dozen legitimate reasons that I might be reading it? Did you truly think to shame me for reading something that I am perfectly within my rights to read? For all your vaunted intellect, can you be that mind-numbingly stupid?'

Fire dances in his eyes as he continues to verbally flay her, and he leans forward, gripping the edge of his desk. She takes a step backwards, helpless in his onslaught. He is towering over her now, and she can't look away from his eyes. She realises that he has stopped speaking and is looking down at her with a look of surprise that fades into a sneer almost immediately.

'I believe you're not here to apologise at all, Miss Granger. I think you're here for another reason entirely.'

Until this moment, Hermione believed she truly wanted to apologise for harming him, but his words hit their mark, and her knees threaten to buckle as she grasps the effect that his voice and his fury are having on her. Her heart is hammering in her throat in elation that he's divined the truth and absolute panic.

She takes a bold step forward so that her hips brush the front of his desk. 'Yes.'

The word, spoken calmly and clearly, breaks the spell, and he sits down once more and takes up his grading quill. 'Detention. If you must indulge in schoolgirl fantasies, I suggest you keep them to yourself, as they are as unwelcome as they are a waste of my time. Remove yourself from my classroom immediately.'

Hermione blinks in surprise, wondering if she imagined that the fire in his eyes was there in the first place. Wordlessly, she gathers her things, but pauses in the doorway.

'Professor Snape?'

'Two nights of detention.'

'May I borrow the book when you're finished with it?'

She swears his lips twitch. 'A week of detention. And no.'

She nods and leaves the room. In the hallway, she lets out a shuddering sigh.  


~o0o~

To Hermione's immense satisfaction, Lucius Malfoy nearly sprays champagne out his nose. d'Aubigny, or rather, Severus Snape, merely looks at her curiously.

'An interesting toast, _cherie_ ,' he says, still doing his uncanny impression of David Suchet's Hercule Poirot. 'One wonders what you mean by it.'

'It means the jig is up,' says Hermione, sipping her drink. Unsurprisingly, it's delicious. 'Laurence d'Aubigny, while charming and brilliant, is as real as the Easter Bunny.'

A look passes between the two men, and d'Aubigny capitulates with a shrug. 'It is not entirely fair to say so, _ma petite_ ,' he says, sounding only slightly less French. 'The Easter Bunny hasn't published in any of the top journals.'

Hermione grins. ' _Touché_.' She practically vibrates with pleasure as she gathers her notes and gestures for them both to sit. 'I've found a number of potions recipes in the Marquis's journals, though it's obvious that he had far greater ambition than skill. Almost all of them contain base potions purchased at the local apothecary.'

Lucius looks momentarily lost before he grasps the abrupt leap of subject and realises that Hermione isn't going to gloat over her discovery. Severus, who has peeled off d'Aubigny's whiskers and rolled them into a piece of velvet for storage, nods.

'There are several references in the text to bought potions,' he says. 'Fortunately for us, the French levied draconian punishments on those who tried to sell fraudulent or dangerous potions. The third edition of Antoine Parapluie's codex was published a few years before the Marquis was imprisoned and the fourth wasn't finished until after his death, so any potion mentioned in any of our sources is likely to have been created using third edition protocols.'

As he speaks, he scrubs his brows with his handkerchief, turning them progressively darker. Hermione is fascinated by the transformation, which is completed when he lifts the shock of white hair from his head, releasing a spill of silvering black hair across his forehead. The informal, almost romantic style flatters his face in a way that the greasy curtain she recalls never did. The difference between d'Aubigny and this younger man are notable, but the difference between him and the Severus Snape she knew all those years ago could not be more striking.

Lucius is thumbing through Hermione's notes. 'What about this one?' he asks, sliding the parchment across the table so they can both read it. 'It calls for an expired restorative draught, which likely contains mandrake, as well as unicorn blood. The blood alone could account for the broken magic.'

Hermione smiles at Lucius's description of the magic as 'broken.' It's a good way of putting it. 'I don't think so. Unicorn blood is a dark ingredient, but it's more likely to taint power than break it. I don't know that we're looking for anything beyond the spoiled mandrake unless it's some sort of transformative element — something like dragonwort that reacts strongly with mandrake to the point that it interferes with magic's ability to hold itself together.'

'A sort of magical venom,' muses Severus. 'Though I doubt it will be as simple as identifying one. The venom of all known magical creatures has been well-characterised in almost every conceivable dosage.'

'Then perhaps an interference of some sort,' says Hermione. 'The Merlin particles could be a combination of the broken magic and the breaking agent.'

'What about a combination of magical techniques?' asks Lucius, who opens one of the journals.

'Like a hex?' asks Severus.

'Or a repurposed Charm.' He holds out a page containing a recipe that Hermione has faithfully copied out. 'Look at the line preceding.'

_'Brewing this potion calls for the utmost silence.'_

Severus looks thoughtful. 'It also contains a spoilt potion in which mandrake is the active ingredient.'

Hermione stares at the page, trying to imagine what effect a Silencing Charm would have. 'Unbelievable,' she murmurs. She looks at Lucius and Severus in turn, 'Muggles have developed a chemical method of silencing specific sections of genetic material to see what molecular pathways are interrupted. What if de Sade found a Charmed potion to reversibly silence a person's magic?'

'There is no way to know that this potion is what causes the effects described in the text,' said Severus.

Lucius settles back in his chair and sips his champagne. 'There is one way.'

Hermione meets Lucius's eyes to see if he means what she thinks he means. There is clearly an invitation there, and no small amount of mischief.

'No.' 

Hermione is surprised that Severus's voice is so flat. 'Why not?'

'This potion contains ingredients that could permanently inhibit a person's ability to do magic. It would be foolhardy to consider reconstruction from these sources outside a facility with any less then level four magical containment in place.'

'Working for the French Ministry has dulled your sense of adventure, old man,' says Lucius. 'You can't even use mandrake there without filling out three forms and using a union technician to prepare and add it.'

'We also have a number of ways to test a potion that don't involve drinking it ourselves,' says Severus, crossing his arms. 

'We needn't test it on ourselves,' says Hermione. 'But we can see if the colour matches Martaine's description in the book.'

'Not to support Severus's argument any more than necessary,' said Lucius 'but the journal containing this recipe dates from 1794, and _120 Days_ was written decades prior to that. It's altogether possible that the potion as described in the book was a figment of de Sade's imagination. You may recall there were a number of encounters that are impossible, even with magic.'

Hermione recalls several scientifically dubious anecdotes and shudders.

'So where does that leave us?' asks Severus, crossing his arms.

'I think we should leave it up to Hermione,' says Lucius. 'We did promise to be at her disposal.'

Severus looks at her and clearly doesn't like what he sees on her face. 'You cannot be entertaining what Lucius suggests. It would be dangerous and unethical.'

Hermione schools her features to calm. 'Have you ever worked with rotten mandrake root before?'

'Yes. It's volatile and emits toxic fumes if brewed improperly.'

'I haven't. Thus, it would be safer for me to brew with you present. Given that our work here is sanctioned by the owner and rights holder of the primary texts, provided we follow the rules of collaboration as set out between our two institutions, I don't see how this could be considered unethical.'

Lucius's smirk widens. 'My thoughts precisely.'

'You are on holiday,' says Severus. 'Surely there's something else you'd rather be doing.'

Hermione suppresses a grin seeing the put-upon expression she remembers fondly. It wouldn't do to gloat. 'I can't think of anywhere else I'd rather be.'  


~o0o~

After serving a mind-numbing week of detentions with Mr Filch, Hermione returns to the library to research what, if not lycanthropy, is ailing Professor Snape. Her first attempt to ask Madam Pomfrey resulted in being shooed from the hospital wing with a lecture on patient confidentiality still ringing in her ears. 

The next line of inquiry is the Encyclopaedia of Potions, which comprises forty enormous volumes with tiny print and is an exhaustive resource for potions ingredients, their preparations, primary and secondary uses, and instructions for handling them. Her search reveals no commonly cited health problems associated with handling any of the Wolfsbane ingredients except for the Quintaped liver, which, in the words of one expert, should not be handled by anyone, ever.

Next, she turns to what magical medical resources she can find in the library, though apart from medicinal potions books, there aren't many. Mediwizardry, she finds, is largely learned through a rigid apprenticeship system, and its secrets are closely guarded. It's only in desperation that Hermione writes an only slightly disingenuous letter to Healer Claypool, a senior researcher at St Mungo's, explaining that she is considering a career in healing and requesting recommendations for introductory texts on the subject.

To her shock and delight, a flock of owls appears the next day with a warm letter from Healer Claypool and a stack of books so massive that she has to recruit Ron to help her carry them back to Gryffindor tower. She feels Professor Snape's glare between her shoulder blades, but she ignores it. Ron is dead chuffed to be asked for help, which momentarily distracts him from moaning over the upcoming Quidditch match against Slytherin.

That night, she begins to understand how complex healing is, but also how antiquated. Before long, the first pages of Healer Claypool's An Introduction to Magical Ailments and Complaints resemble the Half-Blood Prince's copy of Advanced Potion-Making as Hermione, the daughter of health professionals, begins to ask questions.  


~o0o~

Lucius Malfoy's laboratory looks like it hasn't seen much use in recent centuries, but it's laid out sensibly with a desk for Lucius and all his books by the window, and the bench is large enough to accommodate her and Severus, should they actually attempt brewing. For all of his grousing, he's clearly excited, and neither of them is immune to the history of the place. Still, it's a relief to see some sign of the man she knew, though she is certain that pretending to be d'Aubigny for so many years has softened his edges as much as being the black bat of the dungeons sharpened them. For all that she's thrilled beyond words that she has the opportunity to work shoulder-to-shoulder with him, she's glad that the proud, cranky man that she admired and feared is still reasonably intact after everything he's been through.

As they bicker over the proportion of mandrake to newt knuckles, Lucius occasionally reads aloud sections from the texts that, to her surprise, show some insight into de Sade's knowledge and style of doing magic. She supposes she shouldn't be surprised that Lucius has read every scrap of de Sade's writing, though not for the reason she might have ascribed twenty-four hours before.

He is the de facto curator of a historically significant collection of the Marquis's books and papers, and it may well prove to be scientifically important, too. It's no wonder that he, whose unfortunate political choices have made him nearly as infamous in his home country as his best-known ancestor was in his, should seek to rehabilitate the image of that ancestor. If even the Marquis de Sade wasn't all bad, surely there's hope for Lucius Malfoy. There's certainly a healthy bit of vanity in his actions, of course, but it's also clear that he takes his responsibility very seriously. More seriously than his interest in her, anyway, which has become less flirtatious and more matter-of-fact, to Hermione's relief.

She catches him looking at her as Severus is converting livres to kilograms, and the blood rushes to her cheeks as she realises how she must look to him, looking over Severus's shoulder as he works, eager as she'd been eighteen years ago. And yet, she knows as she returns his smile that her discomfiture is unnecessary.

After a few hours of largely theoretical work and creating lists of known and suspected ingredients, Lucius announces that it's time for supper. Hermione is surprised to realise that she's famished. 

'Fascinating how hungry doing nothing can make one,' Severus grumbles. But his hand is warm in hers as they follow Lucius down the corridor.  


~o0o~

The Slug Club party in Slughorn's chambers is shaping up to be an unmitigated disaster. 

She tries not to think about Ron, but the great pillock's absence is nearly as irritating as his presence. She has tried to make the best of it with McClaggen, but she very quickly realises that as pleasurable as reading about such things can be, she is not at all interested in a bloke who doesn't understand the word 'no.' Fortunately, her D.A. training ensures that she is far quicker on the draw than he is. The vacant look on his face as she hits him with a Confundus Charm is the highlight of the evening thus far.

When she emerges from the curtained alcove, she straightens her robes and spots Harry and Luna and joins them for a few minutes before, to Hermione's dismay, Cormac emerges, shaking his head as if to clear water from his ears. She stops talking midsentence and ducks behind the group of pipe-smoking warlocks. Cormac must have troll blood in him, to have recovered so quickly.

She is soon engaged in talk by a scruffy wizard named Herman who, she quickly gleans, is a member of the Weird Sisters. To Hermione's surprise, he's quite nice and delighted to find that she knows enough about music to discuss nonstandard lute tuning. Hermione is about to recommend the consort she grew up listening to when there's a loud choking sound from behind them. She spots Harry, his face dribbling mead but grinning, standing with Luna and Professors Slughorn and Snape, and beyond that, Filch dragging Malfoy into the party.

Herman looks bewildered, and Hermione explains Draco and Harry's rivalry, which, to Hermione's chagrin, gets Herman talking about Quidditch. She excuses herself to the drinks table, taking care to ensure that Cormac is staring interestedly at an ornamental column before moving out into the open. She seizes a goblet of mead and retreats to a dark shadow where she finds herself next to a tall, slender gentleman in black who seems equally disinclined to speak as he nibbles halfheartedly on a pasty.

From this vantage point, she sees Professor Snape escorting Draco out of the room and Harry close on his heels, putting his hand into his pocket, where Hermione suspects his Invisibility Cloak resides. She sighs. There's no talking to Harry when he's convinced of something. She smiles as she reflects that the same could be said of her.

'What a miserable night,' says the man, tossing the unfinished pasty on a passing _h'ors d'oeuvre_ tray.

'I'll drink to that,' she says raising her glass.

"I don't drink... mead," he says with a sniff. "But I suppose you know that already.'

Hermione takes another look at him. Is he one of the Weird Sisters? No, they're all over with Slughorn. She takes one look at his pale face and the dark circles under his colourless eyes, but his features register as a blank in her memory. She is confident she's never seen him before. 'I'm afraid I don't know who you are, sir.'

He looks at her disbelievingly, but after a moment he laughs and offers her his hand. 'My given name is Lorenzo Boccarosso.'

'I'm Hermione Granger,' she says, shaking his hand. 'Why do you say your 'given name?''

'An astute question,' he says, clearly pleased to have been asked. 'I am also known as Sanguini, leader of the Famiglia Boccarosso.'

Of course—the inability to eat or drink human fare indicate that he's vampire, and she recalls from a long-ago Defence lesson that their clan lords tend to be the oldest and most powerful. A thousand impertinent questions spring to mind about the commonly-held beliefs about vampire culture, habits, and diet, but she notes the dark circles under his eyes again. He's hiding from the rest of the party, too. After a moment's deliberation, she decides not to interrogate him unless he's in the mood to be bothered. 

'Should I call you Signor Boccarosso or Sanguini?' she asks lightly.

He smiles, revealing pointed canines that would be rather frightening if not for the warmth in his eyes. 'Lorenzo, if you please. Now, if you will forgive the liberty, I sense that you have received unwanted attentions.'

Hermione blinks. 'How did you know?'

'First of all, you are hiding in a dark corner with a vampire at a party. Your hair has been mussed and your robe is slightly torn at the neck,' he says, giving an apologetic smile. 'I couldn't help but notice.'

'The situation has been dealt with,' says Hermione tightly.

Lorenzo surveys the crowd. 'The young hulk who seems so fascinated by the surface of the punch bowl. Your work?'

'Yes. I think he's building up an immunity to Confundus Charms.'

'Such a man deserves more than a Confundus Charm.'

'It's not entirely his fault. I did invite him.'

'Did you invite him to take such liberties?' asks Lorenzo, his pale eyes flashing red. 

'He seemed to think it was part of the invitation.'

Lorenzo waves his hand dismissively. 'I do not understand where a man would get such an idea.'

'I don't know how much you know about the politics here, sir, but there is a movement afoot that seeks to impose a strict social hierarchy, and people from nonmagical families, like me, are very close to the bottom of it. Cormac comes from an old wizarding family and perhaps feels that he's due the deference of those lower on the social ladder.'

'You agree with this?'

'Of course not! It's what I and my friends are fighting against.'

'Good. Because where I come from, power is power, regardless of one's parentage. You, little one, crackle with it. I hope for your cause's sake that mercy stayed your hand rather than the feeling that you haven't the right to wield your full strength.''

Hermione is at a loss for words. Fortunately, he does not seem to require a response. A house-elf with a tray wanders by, and Hermione catches a whiff of the spicy prawns on skewers. Lorenzo covers his mouth and nose with a handkerchief. Of course — the garlic.

'Is this England or is it France?'

'Professor Slughorn is something of a gourmand,' says Hermione apologetically.

'There appears to be little that he doesn't eat.'

Hermione laughs, and the sound falls into a lull in the room's conversation. To her dismay, Professor Slughorn turns and sees them.

'That's where you've got to, Sanguini!' he says jovially. He wraps an arm around each of them and ushers them to the centre of the room, where a group of old men is gathered. 'I see you've met Hermione Granger. One of my top students, had the book practically memorised on the first day! And a close friend of Harry Potter's,' he says, giving one of the gathered wizards a knowing wink.

'Hermione was kind enough to explain to me some of England's cultural traditions and the current political climate,' says Lorenzo, giving her a wry smile. 

The smile on Slughorn's face falls slightly. 'Not a terribly festive subject. But won't you have some of the blood sausage, Sanguini? I ordered it especially for you.'

'Thank you, but no. I have little appetite. I encountered some garlic earlier, and I'm afraid I've not yet 'built up an immunity' to it, as Hermione would say.'

'What a charming turn of phrase,' says one of the older wizards. 'I've never heard it before. Is it one of your new-fangled expressions?'

Hermione feels her face flush. 'It's a Muggle phrase, sir, referring to the immune system's response to repeated exposure to a pathogen. Immunity is conferred when the body can produce enough antibodies to destroy the pathogen before it makes one sick.'

'An answer taken verbatim from a book, no doubt.' 

Hermione turns and finds Professor Snape looking down his nose at her. She smiles and succumbs to the reckless urge to answer saucily. 'But correct in essentials, sir?'

He scowls at her, and Slughorn roars with laughter. 'You're going to have to work harder than that to intimidate this one, Severus.'

'I imagine very little intimidates Miss Granger, unless it's the loss of a large number of house points or the threat of a poor mark.'

'Pax, Severus!' exclaims Slughorn. 'It is Christmas! I won't have you deducting points!'

'To blazes with Christmas,' says one of the smallest wizards, who brandishes a large ear trumpet. 'I want to hear more about immunity. Why don't Muggles simply take Pepper-Up?'

'Pepper-Up Potion merely treats the symptoms, not the infection,' says Professor Snape, giving Hermione a quelling look. 

She ignores him. 'Muggle science is trying to work out why we become sick and to prevent it. For example, one method they use to prevent disease is vaccination, where partial or heat-killed germs are introduced to the body to provoke the immune response without sickening the patient. That way, if the person ever encounters the germ, the immune system kills the germs before they can make the person sick.'

Even Slughorn appears slightly interested. 'One of my old students, Vanessa Claypool, is a researcher at St Mungo's, you know.''

'Oh yes! I wrote to her about potentially pursuing a career in healing, and she was kind enough to send me some books to read.'

Professor Snape makes a scoffing noise, which both of them ignore. 'I would be delighted to write you a letter of recommendation,' says Slughorn, radiating avuncular pride for a moment before making a beeline for a drinks tray passing his vicinity.

Hermione is disappointed to see that one of the men has commandeered Sanguini and steered him off towards several tall, athletic-looking witches, and she finds herself left alone with Professor Snape. Now that he's standing quite close to her, she sees that he has circles under his eyes to rival the vampire's. Could he be— ? Definitely not. She's seen him in sunlight at Quidditch matches.

'Healing is clearly not your field, Miss Granger.'

Rather than explicitly defy his order not to speak to him on subjects not pertaining to Defence, she merely cocks an interrogative eyebrow at him.

'Watching you show off for Horace's cronies was enough to make anybody sick.'

On any other night in any other circumstances, Hermione would have been mortified. But tonight, after successfully fighting off McClaggen, befriending a vampire lord, and not making an arse of herself in front of Professor Slughorn's friends, she feels more confident than she has in weeks. She feels powerful tonight — apparently she crackles with it. 

'And I didn't even need to expose you to aconite fumes this time,' she says.

She can't tell if it's humour or anger that makes his lips twitch. 'Detention.'

And suddenly, his knowledge of the immune system and his symptoms crash together in her brain, and she fairly vibrates with excitement at the only explanation that makes sense of it all. 'When did you develop the allergy, sir?'

'Lower your voice, foolish girl! Two nights of detention!'

He hasn't denied it! Adrenaline floods her veins. 'Is it only the aconite? Or is it other things, too? The silver? Hawthorn?'

'Silence,' he hisses, seizing her glass of mead. 'You've clearly had enough, Miss Granger. I will see you back to your common room before you get into any further mischief.'

He all but drags her from Professor Slughorn's quarters, and as they're rounding the stairs, Cormac staggers out from behind a suit of armour. 

'There you are,' he says to Hermione, seizing her other arm roughly, completely oblivious to Professor Snape's presence. 'I've been looking all over for you. We're not finished.'

'I beg to differ, McClaggen.' The wand is in his hand in the blink of an eye. 'Obliviate!'

McClaggen sags to the floor, catatonic. Professor Snape gives her a poisonous smile. 'I trust you'll be more emphatic in discouraging him in the future.'

'Y-yes, sir.'

He whisks off down the corridor, and she follows dutifully.

When they reach the Fat Lady's portrait, he gives the password, and the portrait swings open.

'Thank you for dealing with McClaggen, sir. He won't catch me at a disadvantage again.'

'I trust that he won't. And Miss Granger?'

She pauses in the doorway.

'Should you desire a letter of recommendation to Healer Claypool, I am far better qualified to write a letter of recommendation than Horace, having endured many more years of your intellectual curiosity.'

'Thank you, I— that is, thank you,' she says lamely.

'Don't thank me until you've met Healer Claypool. You are of such similar temperament that you will either be friends within minutes or mortal enemies.'

She has no desire to stop the smile that spreads across her face. 'I'll bear that in mind. Thank you, sir.'

He makes a dismissive noise, but Hermione catches a ghost of a smile on his lips as he stalks off down the corridor.  


~o0o~

After a five-course meal and some outrageous anecdotes from Lucius, the three of them retire to the laboratory, and Hermione accepts a glass of Port that she swears is refilling itself.

Severus and Lucius are arguing over a fine detail of translation, and Hermione decides that if she doesn't do something, she is going to fall asleep. She rises from the bench and begins taking stock of the ingredients, most of which appear to be quite old.

The men look up from their parchment.

'Are you planning to brew tonight?' asks Lucius.

'I'm checking your stocks for expired ingredients,' she says, pulling the stopper out of a bottle of frogwort and sniffing experimentally. It's not only gone off, it's gone rancid. She replaces the stopper with a grimace. 'We can send an elf to the apothecary to restock if needed.'

To her surprise, both men cast Bubble-Head Charms. 'Are you allergic, too?' she asks Lucius.

It's a simple enough question, or so she thinks. However, the expressions of bonhomie are immediately wiped from her companions' faces. 'Too?' asks Lucius, looking at Severus.

'Answer the healer's question, Lucius.'

'I hardly think it's relevant.'

'It may well be,' says Hermione, leaving the bottles on the workbench. 'In epidemiology, they use the word 'cluster' to describe a group of unrelated people who develop similar medical conditions. The larger the sample size, the more likely it is that we can isolate what it is that's made them ill.'

'A sample size of two is hardly a trend,' sneers Severus. Hermione is momentarily taken aback when she realises that he's never told Lucius about his disability, and it seems that Lucius has been keeping secrets of his own.

'No, but when the sample for potentially life-threatening magical allergies includes six other former Death Eaters, all of whom have received treatment at St Mungo's, then the addition of two is statistically significant, don't you think?'

Both men glare at her. When she meets their ire with an interrogative look, they glare at one another.

Severus is the first to look away. 'It started with silver,' he says, swishing to the far side of the lab. 'Then aconite. It wasn't the ingredients by themselves, only when used in a potion. I was able to manage it for a while by writing the instructions on the boards and supervising instead of demonstrating, but after the Dark Lord's return, I finally reached the point where I could no longer tolerate being in the same room where brewing occurs without effect.'

'I had no idea it had been going on so long,' says Hermione. Severus's hands-off teaching style makes a great deal more sense now. 'When did you first notice a problem?'

'Shortly after I was appointed Potions Master at Hogwarts.'

Lucius has an unfamiliar expression on his face. It takes Hermione a few moments to recognise it as pity. Severus notices it too and makes a dismissive noise.

'Compared to hiding my true allegiances, concealing a magical allergy was simple.'

'I can imagine,' says Lucius. 'My own experience started in my seventh year at Hogwarts. I found myself feeling quite weak during the carriage ride to the school. In those years, Rebeus Hagrid was merely the groundskeeper, not the Care of Magical Creatures instructor, so I didn't know that it was the Thestrals that were causing the problem. However, I understood when I visited my father's stables over the holidays. He bred Abraxans, you see.'

Severus is watching Lucius carefully and nods, seemingly unconsciously. The puzzle pieces are falling together for him, as well.

'When he passed, I had to clear the Manor of his winged horses, Crups, and my late mother's Kneazle. The peacocks were all that remained, and I had to stop giving them magical feed. Even the house-elves made me feel weak, and I admit, I took out some of my frustrations on them.'

Hermione regarded him curiously. 'But you have house-elves now.'

'After the house-elf Dobby left my service, I noticed that the Hogwarts elves did not affect me in the same way that my own did. After sending one of my elves to investigate, I found that the Hogwarts elves had more than enough tasks to keep them busy, whereas I had a houseful of elves and considerably fewer domestic duties. Like the horses my father once kept, I realised that keeping the elves busy would make them less likely to cause me mischief, even if they weren't doing it deliberately.'

'So the idle elves acted like reservoirs of magical energy, which exacerbated your allergies?'

'That was my reasoning at the time,' says Lucius.

'Exactly what did you do to make your elves more magically active?' Severus's arms are crossed, but his expression is more curious than forbidding.

Lucius smiles. 'Do you recall your home being significantly less sty-like when you returned?'

'No.'

'You wouldn't. But I dispatched the elves to friends and neighbours to clean when and where they would not be seen.'

'Your closest neighbours are Muggles, Lucius,' says Severus.

'As if they would complain.'

Hermione begins to giggle. 'Lucius Malfoy's Clandestine Cleaning Service. Still, it's impressive that you solved the problem well enough to have never been sent to hospital with magical depletion.'

'Not in England,' says Lucius.

'And certainly not when one is harbouring a fugitive Potions master,' says Severus.

'You never gave any sign that brewing caused you distress,' says Lucius.

'That's because I always brewed your Replenishing Potions by proxy. I'm well enough as long as I don't touch the ingredients and protect myself from the fumes with a Bubble-Head Charm.'

Lucius looks at him disbelievingly for a moment and then begins to laugh. 'You were the one who taught my elves to prepare potions ingredients.'

Severus smirks. 'Did you really think the Cordon Bleu taught house-elves?'

Hermione clears her throat to keep from laughing, and it also serves to remind the men of her presence. "Isn't it interesting that you both began to exhibit symptoms shortly after joining Voldemort?'

It's a testament to time and their characters that neither flinches when she says the name.

"A correlation is not causation, _ma petite_ ," says Severus.

She smiles to hear d'Aubigny's affectionate nickname delivered with Severus's dry humour. "Of course not. But allergies produce broken magic, as Lucius describes it, as does this lost magic of de Sade's. Broken, or split. Might exposure to Voldemort's soul-splitting experimentation have detrimental effects on those closest to him?'

Severus frowns. 'Conjectural at best.'

'You make it sound like a disease,' says Lucius.

'Perhaps it is, in a sense,' says Hermione, a new thought occurring to her. 'Perhaps splitting a soul or separating a person from his or her magic creates something that the magical self finds anathema. In a person's attempt to destroy the residue, it begins to attack magic outside itself indiscriminately.'

'It sounds elegant. But so does Byron's description of the universe as nested crystalline spheres. There's no evidence that's what's occurring,' says Severus.

'Of course there's evidence—I'm here, aren't I?' Heremione runs her fingers through her escaped curls. 'Magical allergies are becoming more and more common since around the time Voldemort decided to shred his soul in unprecedented ways. What if splitting the soul is like splitting the atom? Fallout from the cataclysm can last for hundreds of years.'

'Who's Adam?' asks Lucius, looking confused. Both Severus and Hermione shush him.

'Think about the potential spread. Voldemort was in the Ministry. He was at Hogwarts. He lived in Lucius's home. He was in any number of places where he could have exposed people to whatever this is.'

'And de Sade's experiments took place in my dungeon,' says Lucius dryly. 'By that account, I should be the sickest of us all.'

Severus gives him a hard look. 'You spent the year that the Dark Lord lived in your house looking like death warmed over.'

'It's true that I was ill while the Dark Lord lived in residence. But I assumed it was caused by the presence of that beastly snake. If Hermione is correct about the split soul being the cause of the problem, the effect would have been twofold.'

'It must have been awful,' says Hermione, sympathetically.

'It was neither the first nor last time I have been grateful for Severus's friendship.'

Hermione feels a hot flare of indignation on their behalf. Voldemort's experimentation claimed far more victims than she had ever supposed, and to drain people of magic is an unforgivable violation. And the allergy has not only interefered with their magic but also the men's fundamental relationship to the practise of magic, since Lucius can no longer abide the creatures he once loved, and Severus cannot brew.

'I want to make the potion,' she says. 'If there's any way I can treat this, I want to start work on it as soon as possible.'

'It's late, my dear. I'm afraid I'm not as young as I once was,' says Lucius, sliding comfortably down in his chair by the fire. 

Hermione looks at her half-full glass of Port and sighs. She catches Severus's eye. 'Tomorrow, then?'

To her surprise, Severus sits down next to her on the settee and meets her gaze levelly. 'You know there's no chance of success tomorrow. The textual sources are too vague and disparate, the theoretical framework is unclear at best, and you simply haven't the brewing experience. It's going to take months of research, planning, and experimentation before we have sufficient data on to move forward with testing.'

She puts her hand over his and presses it. 'I know that. I've never thought tomorrow would be the end, though I had hoped it might be the beginning.'

He looks at her, his eyes warm despite the stillness in his face. 'I think that much, at least, can be arranged.'  


~o0o~

Her posterior is completely numb, and she can't tell if it's from the hardness of the dungeon floor or its inherent chill. But the sweet taste of Felix Felicis is still warm on her tongue, and Luna has been wonderful company. For the first time, she understands that behind the outlandish theories is a valuable ability to speak the truth, and Hermione feels lucky to see this side of Luna.

The door to Professor Snape's chambers is resolutely closed, as it has been for the past hour, and Hermione begins to wonder if the Felix Felicis Harry left them is sufficient to keep Draco Malfoy and his plans at bay. And then she hears it — the sound of feet pounding down the stairs and then slapping loudly against the stone floor.

To her surprise, Professor Flitwick, his face bright red with exertion, tears past their hiding place at a speed she didn't know the tiny man was capable of and pounds on Professor Snape's door.

'Severus!' he squeaks, breathing hard. 'Severus, you must come at once! They're here!'

The door opens quickly to admit him and shuts before Hermione and Luna have the chance to move from their alcove. Before they can knock, Professor Snape opens the door to reveal Professor Flitwick lying on the floor, unconscious.

'Death Eaters in the castle.' Hermione isn't sure if it's her own mind connecting the dots or Felix's suggestion, but she feels the truth of her statement.

'They got Professor Flitwick,' says Luna sadly.

Professor Snape's face is as still as marble and as pale. 'So it would seem. Filius isn't well. See to him now if you can, and take him to the Hospital Wing when it's safe. And above all, do not make yourselves targets.'

Luna Levitates Professor Flitwick's unconscious body and takes off down the corridor. Professor Snape brushes Hermione, but she places her hand on his arm. 'Is there anything I can do to help?'

'Don't touch me,' he whispers, his voice flat and hard.

In a glance she understands that her hand is resting over his Dark Mark, and there is anger on his face, but rather than shake her hand off, his scowl seems troubled, and it's not so much directed at her as at himself. A ball of apprehension settles in her stomach. The situation must be dire indeed if Severus Snape hesitates to face it. She squeezes his forearm, and his hand curls into a fist instinctively.

'I believe in you,' she says quietly, and then Felix is there, pushing her forward on to her toes.

She seizes the front of his robes and kisses him full on the mouth. 

She doesn't need Felix to tell her to close her eyes or open her mouth as he gasps in surprise or enjoy the moment when he begins to kiss her back. His lips are strong, his mouth is warm, and he tastes savoury, with a hint of herbal bitterness. His arms encircle her so tightly that she can't breathe, but she doesn't care. She buries her fingers in his hair and holds him as tightly as she can. He's breathing hard through his nose, desperately clinging to her and this strange place where she can offer him comfort and he can accept it, just once, before confronting something so terrible that neither wants to contemplate it. She has no idea how long they stand there holding one another until his arms release her and his hands go to her shoulders, gently pushing her away.

When her eyes come back into focus, he is looking at her as though he's never seen her before, and in his face there is such naked anguish that she longs to take him in her arms again, but both she and Felix know it's not a good idea. And then his face is the same impassive mask that she knows too well, and he flees down the corridor. 

Hermione watches him go, her heart pounding in her throat.

They will not speak again for eighteen years.  


~o0o~

Ninteen years and two hundred twelve days later, Hermione steps off the broken end of the _Pont Saint-Bénezet_ and approaches Lucius's home once more. A stunningly white peacock and silver peahen peck between the cobblestones encircled by several dark brown chicks. When the male spies her, he fans his tail, and to her delight, it sends blue-white sparks dancing towards her, and she laughs, delighted by the display's frivolous beauty.

She pauses at the hitching post and sets her satchel on it, checking for the umpteenth time to ensure that she's remembered the letter from _The Journal of Alchemical Healing_ , which she's already committed to memory but doesn't want Severus to know it.

_Dear Healer Granger,_

_In re: your paper 'A New Paradigm for Treating Fallout-Induced Magical Sensitivity,' which has been accepted for next month's issue, along with Laurence d'Aubigny's paper 'Mechanisms of Magical Decay' and the appendix of historical documents from the de Sade estate, we took the liberty of sending the abstract to our subscribers, since we cannot justify making the ill wait any longer than necessary for treatment. We have been overwhelmed by the response. Not only have we received the largest number of single-issue pre-orders in our publication's history, we have also been inundated by requests from Healers for your protocols. We hope that, given the dire state of those afflicted with magical allergies, you and your co-author will consent to us providing the recipe to healing practitioners prior to publication and have enclosed the necessary release forms. We eagerly await your response._

_Yours sincerely,_

_Messrs. Jameson and Jenson_  
_Eds._

She smooths the parchment flat between the leaves of her book and returns it to her satchel, and when she looks up, she sees Lucius watching her from the library window. She can't see his face clearly, but the gesture he uses to summon Batty is unmistakable, and she knows there will be champagne momentarily.

She can't control the little leap her stomach executes when the front door opens, and Severus appears as himself. She has an odd moment of surreality as she sees Professor Snape's characteristic scowl settle upon his face, but his mouth twitches, and he is her Severus once more.

Abandoning all pretence of decorum, she hoists the satchel over her shoulder and runs to him. His lips are warm on her forehead, and then on her lips as she raises her face to him. He smells of freshly-chopped herbs and the medicinal scent of juniper. After kissing him into an impressive state of smugness, he takes her hand, and together they cross the threshold of Lucius's chateau.

She has no idea what lies ahead any more than she has at any point in her life, but the auspices are favourable indeed.  


~o0o~

The End  


~o0o~

**Author's Note:**

> I am, as always, indebted to Mr. 42's beta-reading prowess, and the eternal patience of Bluestocking79, who has improved this story beyond the lot of mortals. The title is taken, sort of, from Hercule Poirot: "Only by interrogating the other passengers could I hope to see the light, but when I began to question them, the light, as MacBeth would have said, thickened." The long quote attributed to de Sade is actually his, though I also wrote some fake magical bits in the style of 120 days. IMHO, that quotation is the only interesting part of the whole book. I read it so y'all don't have to. As previously noted, this is a finished work that was written for a specific recipient in response to particular prompts, and as such, concrit is not being solicited.


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